Adaptive optical devices with controllable focal power and aspheric shape

ABSTRACT

A fluidic lens may include an optical surface configured for deflection dominated by bending stress. An adjustable concentric load may be applied to the optical surface to cause a clear aperture region of the optical surface to deflect with generally spherical curvature. Adjusting the concentric load controls the radius of curvature. An adjustable uniformly-distributed load may be applied to the optical surface by fluid pressure that causes the clear aperture region to deflect with an aspheric shape. Adjusting the pressure controls the asphericity of curvature. First and second fluids having similar densities and different refractive indexes may be disposed on either side of a deflectable optical surface to help balance gravitational loading on either side of the optical surface, thereby reducing gravity-associated aberrations.

CLAIM OF PRIORITY

This application is a continuation of commonly assigned U.S. patentapplication Ser. No. 14/887,164, to Robert G. Batchko et al., entitled“ADAPTIVE OPTICAL DEVICES WITH CONTROLLABLE FOCAL POWER AND ASPHERICSHAPE”, filed Oct. 19, 2015, now U.S. Pat. No. 9,500,782, the entirecontents of which are incorporated herein by reference. U.S. patentapplication Ser. No. 14/887,164 is a continuation of commonly assignedU.S. patent application Ser. No. 13/598,539, to Robert G. Batchko etal., entitled “ADAPTIVE OPTICAL DEVICES WITH CONTROLLABLE FOCAL POWERAND ASPHERIC SHAPE”, filed Aug. 29, 2012, now U.S. Pat. No. 9,164,202,the entire contents of which are incorporated herein by reference. U.S.patent application Ser. No. 13/598,539 is a continuation-in-part ofcommonly assigned U.S. patent application Ser. No. 13/301,492, to RobertG. Batchko et al., entitled “FLUIDIC LENS WITH REDUCED OPTICALABERRATION”, filed Nov. 21, 2011, now U.S. Pat. No. 8,605,361, theentire contents of which are incorporated herein by reference.

U.S. patent application Ser. No. 13/301,492 is a continuation-in-part ofand claims the priority benefit of commonly assigned U.S. patentapplication Ser. No. 12/706,637, to Robert G. Batchko et al., entitled“FLUIDIC LENS WITH REDUCED OPTICAL ABERRATION”, filed Feb. 16, 2010, nowU.S. Pat. No. 8,064,132, the entire contents of which are incorporatedherein by reference. U.S. patent application Ser. No. 12/706,637 claimsthe priority benefit of commonly assigned U.S. Provisional PatentApplication No. 61/171,044 to Robert G. Batchko et al., entitled“FLUIDIC LENS WITH REDUCED OPTICAL ABERRATION”, filed Apr. 20, 2009, theentire contents of which are incorporated herein by reference.

U.S. patent application Ser. No. 13/598,539 is a non-provisional of andclaims the priority benefit of commonly assigned U.S. Provisional PatentApplication No. 61/529,174, to Robert G. Batchko et al., entitled“FLUIDIC LENS WITH IMPROVED ASPHERIC SHAPE AND A METHOD OF REDUCINGPRESSURE EXCURSIONS IN A FLUIDIC LENS BOUNDED BY BENDING MEMBRANES”,filed Aug. 30, 2011, the entire contents of which are incorporatedherein by reference.

U.S. patent application Ser. No. 13/598,539 is a non-provisional of andclaims the priority benefit of commonly assigned U.S. Provisional PatentApplication No. 61/539,823, to Andrei Szilagyi et al., entitled“ADAPTIVE OPTICAL DEVICES WITH CONTROLLABLE FOCAL POWER AND ASPHERICSHAPE”, filed Sep. 27, 2011, the entire contents of which areincorporated herein by reference.

U.S. patent application Ser. No. 13/598,539 is a non-provisional of andclaims the priority benefit of commonly assigned U.S. Provisional PatentApplication No. 61/539,891, to Robert G. Batchko et al., entitled“ADAPTIVE OPTICAL DEVICES WITH CONTROLLABLE FOCAL POWER AND ASPHERICSHAPE”, filed Sep. 27, 2011, the entire contents of which areincorporated herein by reference.

FIELD OF INVENTION

This invention generally relates to liquid lenses and more particularlyto fluidic liquid lenses.

BACKGROUND OF THE INVENTION

The prior art contains a number of references to adaptive optics (AO),lenses and systems. The development of AO over the last several yearshas led to important advances in multiple fields; this has been madepossible by virtue of AO's ability to reduce the number of moving parts,foot print and design effort associated with optical systems. One areaof AO that has received considerable attention is the liquid lens. Inthese devices, a volume of fluid typically provides a reconfigurableoptical medium. Selected optical properties of the lens are adjusted bymanipulating various properties of the fluid and/or the boundaryconditions of the compartment or substrates housing the fluid.

Typical liquid lenses fall under one of three categories:electrowetting; liquid crystal (LC); or fluidic. A notable example of anelectrowetting lens is provided by Bruno Berge, et al., “Lens withvariable focus”, PCT Publication No. WO 99/18456. In that system, acompartment houses two immiscible liquids having different refractiveindexes. The interface between the two liquids can vary fromsubstantially flat to substantially spherical in curvature and islargely determined by the contact angle formed between the interface andthe wall of the compartment. The curvature of the interface anddifference in indexes between the two fluids serves as a lens for lighttransmitted across the interface. The contact angle will change inresponse to a voltage applied across the compartment wall. A change involtage will result in a change in the curvature of the interface andfocal power of the lens. Although the electrowetting approach yields aconveniently compact system with low power requirements and fastresponse, it is difficult to maintain a stable interface for clearapertures greater than about 5-mm diameter.

LC lenses generally utilize the fact that liquid-crystal molecules,which are shaped like tiny rods, can change their orientation in anelectric field. Under sufficient field strength, a substantial amount ofthe molecules can line up parallel to the field. This alters therefractive index, and hence the focal power, of the material. Bytailoring the field, substrate and/or LC layer, various opticalproperties can be controlled. In “Adaptive Liquid Crystal Lenses,” U.S.Pat. No. 6,859,333, Ren, et al., teach a LC lens based on a homogeneousnematic LC layer sandwiched between two transparent substrates. Thefirst substrate includes a spherical or annular ring-shaped Fresnelgrooved transparent electrode patterned on its inner surface, while thesecond substrate includes a transparent electrode coated on its innersurface. When a voltage is applied across the LC layer, acentro-symmetrical gradient distribution of refractive index within theLC layer occurs. The difference in indexes of the LC layer and patternedsubstrate causes light to focus. By controlling the applied voltage, thefocal length of the lens can be tuned continuously. While this deviceovercomes many limitations typical of other LC lenses, such as strongastigmatism, distortion and light scattering, it suffers from a slowresponse time. For example, the focusing time of a 6-mm diameter lenshaving a 40-micron-thick LC layer is approximately 1 second.

The family of fluidic lenses embodies a wide variety of designs andfeatures, however lenses of this type typically comprise the followingbasic structure: (a) a lens compartment filled with a transparent andincompressible fluid; (b) the compartment is bounded around its sides bya sidewall and on its optical faces by a pair of opposing opticalsurfaces wherein at least one of the optical surfaces (a “membrane”) isformed from an elastic material and is thus capable of elastic strain;(c) an actuator delivers an actuation force (or “load”, “loading” or“applied load”) to the compartment or fluid, resulting in apressurization of the fluid and a deformation of the membrane; and (d)once the actuation force is diminished, the restoring or elastic forceof the membrane may contribute to the restoration of the membrane to itsoriginal or non-actuated state. The change in shape of the membrane anddifference in index of refraction between the fluid and medium externalto the compartment, result in a change in focal power of the fluidiclens. A system has also been demonstrated (see J. Chen et al., J.Micromech. Microeng. 14 (2004) 675-680) wherein only one lenticular bodyis provided, bounded on at least one side by an optically clear,compliant membrane. In that system, the refractive power of the lens iscontrolled by pumping in or out a controlled amount of fluid, therebychanging the curvature of the bounding membrane. That system stillsuffers from the disadvantage that the pressurized fluid source islocated remotely from the compartment. This makes the form-factor of thewhole system inconvenient.

While fluidic lenses are capable of overcoming many problems associatedwith liquid lenses, such as slow response time, instability of largeapertures and optical losses, certain limitations remain. For example,in order to reduce the force required by the actuator, it is oftendesirable for the membrane to be highly compliant and have low elastic(or Young's) modulus, typically in the range of about 0.05 to 2 MPa.However, such low elastic modulus may cause the lens to be susceptibleto disturbances, such as instabilities in focus and tilt due to forcesof acceleration, and aberrations, such as coma, which may be due togravitational forces. An approach to mitigating this limitation that hasbeen taught is pre-tensioning of the elastic membrane during lensfabrication, e.g., as described in U.S. Pat. No. 7,697,214 to Robert G.Batchko et al entitled “FLUIDIC LENS WITH MANUALLY-ADJUSTABLE FOCUS”,the entire contents of which are incorporated herein by reference.Pre-tensioning reduces the compliance of the membrane, making iteffectively stiffer and thus more resistant to the effects of gravity.Nevertheless, is some instances (for example, lenses with small f/#'s orlarge apertures) coma and other gravity-induced aberrations persist.

Another inherent disadvantage of many low-elastic modulus membranematerials (for example, polydimethylsiloxane or PDMS) is theirpermeability, or inability to effectively block the passage of somegases and fluids. Such permeability may result in air bubbles developingin, or fluid leaking out of, the fluidic lens. These effects candiminish the durability, lifetime, optical quality, dynamic range andother performance properties of the lens. Some approaches to solvingthis problem may include coating the membrane with a high-barriermaterial or increasing the thickness of the membrane. However, theseapproaches can result in disadvantageous effects such as increasing thecomplexity of fabrication, optical scatter and loss, and aberrations.

Yet another inherent disadvantage of typical fluidic lenses is that theshape profile and resulting optical properties of the lens aresubstantially governed by the tensile elastic properties of the membrane(e.g., Young's modulus, thickness, and amount of pre-tensioning) andfluid pressure. In conventional optics, it is often desirable for thesurface of a lens to have a spherical, or prescribed aspheric, profile.However, in the case of fluidic lenses, the highly compliant nature ofthe membrane generally results in a strong nonlinear dependence of themembrane profile on fluid pressure. Thus, instead of maintaining aspherical profile independent of fluid pressure (i.e., fluid pressureonly affecting the radius of curvature), the membrane profile of thefluidic lens may deviate significantly from spherical, with the amountof deviation being dependent on fluid pressure. Such complexdependencies can severely limit the ability to control the opticalproperties (such as aberrations, the conic constant and other opticaleffects) of fluidic lenses.

More recently, another co-pending application Ser. No. 12/706,637(“VARIABLE-FOCAL-LENGTH FLUIDIC LENS WITH REDUCED OPTICAL ABERRATION”,to Batchko et al.) taught means by which the aforementioned limitationscould be largely overcome. A key element in overcoming these limitationswas the use of membranes constructed from intrinsically stiff materials,such as glass or optical plastics. In such stiff materials the nature ofthe deformation is substantially a bending strain, whereas in the caseof compliant membranes (such as those composed of elastomer films) thedeformation is substantially an elastic strain. In such membranes thatdeform by bending strain, their stiffness is generally sufficient toresist the effects of gravity. However, when the lens profile is nolonger afflicted by gravitationally-induced optical coma, sphericalaberration (the next higher order aberration commonly associated withfluidic lenses) may now become the dominant aberration. It is well knownin the art that spherical aberration is not only associated with fluidiclenses, but also in general with all types of lenses, including staticlenses composed of solid materials and other types of adaptive lensessuch as liquid crystal and electro-optic lenses. Solutions for providinga fixed (or “static”) spherical correction are known in the art (forexample, Schmidt corrector plates). Likewise, dynamic wavefrontcorrection can be accomplished by deformable mirrors [Saito et al., U.S.Pat. No. 7,520,613], liquid crystal spatial light modulators [Barnes etal., U.S. Pat. No. 5,018,838] and mechanical movement of static elements[Alvarez, U.S. Pat. No. 3,305,294 and Simonov et al., WPO InternationalPublication Number WO 2011/019283 A1]. Nonetheless, these solutionssuffer from limitations including: high insertion loss; limited range ofoptical waves of wavefront correction, mechanical complexity andreflective-only (i.e., only non-transmissive or refractive) design.

Despite their low cost and other advantages, the abovementionedlimitations and inability to achieve optical performance at a levelcomparable to that of conventional lenses has thus far prohibiteddevelopers from substantially adopting liquid lenses in numerous opticalproducts and applications.

Thus, there is a need in the art for an adaptive optical device thatovercomes the above disadvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

Objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to theaccompanying drawings in which:

FIG. 1 shows a wedge-shaped section view of a fluidic lens membranehaving a high elastic modulus and being fixed in a rigid mountingconfiguration.

FIG. 2 shows a wedge-shaped section view of a fluidic lens membranehaving a high elastic modulus and being fixed in a flexible mountingconfiguration.

FIG. 3 shows a deflected optical surface with a resulting inflectionpoint close to a support.

FIG. 4 shows an optical surface having a fixed edge support anddeflected by fluid pressure.

FIG. 5 shows an optical surface with a simple edge support and deflectedby fluid pressure.

FIG. 6 shows an optical surface with a fixed edge support and simpleinner support and deflected by a concentrated ring-on-ring load.

FIG. 7 shows an optical surface with a simple edge support and a simpleinner support and deflected by a concentrated ring-on-ring load.

FIG. 8 shows an optical surface with a fixed edge support, a simplepoint support, and deflected by a pin-on-ring load.

FIG. 9 shows an optical surface with a simple edge support, a simplepoint support, and deflected by a pin-on-ring load.

FIG. 10 shows an optical surface with a fixed outer edge support, asimple inner ring-shaped support, and a simple point support.

FIG. 11 shows an optical surface with a fixed edge support, a simpleinner support, and deflected by a concentric load and fluid pressure.

FIG. 12 shows an alternate configuration of an optical surface with afixed edge support, a simple inner support, and deflected by aconcentric load and fluid pressure.

FIG. 13 shows and optical surface with a simple edge support, a simpleinner support, and deflected by a concentric load and fluid pressure.

FIG. 14 shows an optical surface with a fixed edge support, a simpleinner support, a simple pin support, and deflected by a concentric load,a pin-on-ring load and fluid pressure.

FIG. 15 is a three-dimensional cross-sectional view of a fluidic opticaldevice with compliant edge supports, two deflectable optical surfacesand dual actuators.

FIG. 16 is a three-dimensional cross-sectional view of a fluidic opticaldevice with compliant edge supports, two deflectable optical surfaces,dual actuators and simple inner support for providing a ring-on-ringload.

FIG. 17 is an exploded view of a fluidic optical device similar to thatdepicted in FIG. 16.

FIG. 18 is an exploded view of a fluidic optical device that includescompliant edge supports, two deflectable optical surfaces, dualactuators and perforated simple inner support.

FIG. 19 is a cross-sectional side view of a fluidic optical device thatincludes compliant edge supports, two deflectable optical surfaces, dualactuators and perforated simple inner support, and shown in anundeflected state.

FIG. 20 is a cross-sectional side view of a fluidic optical device thatincludes compliant edge supports, two deflectable optical surfaces, dualactuators and perforated simple inner support, and shown in a deflectedstate.

FIG. 21 is a cross-sectional side view of a fluidic optical device thatincludes compliant edge supports, two deflectable optical surfaces, dualactuators and perforated simple inner support, further including apressure control actuator.

FIG. 22 is an exploded view of a fluidic optical device with deflectableand rigid optical surfaces.

FIG. 23 shows a simple perforated support with channels for fluid flow,radial protrusions to assist in alignment and flexible linkages forproviding axial compliance.

FIG. 24 is a cross-sectional view of a fluidic optical device with innersupport having channels for fluid communication with an annularcompliant reservoir and bladder.

FIG. 25 is an exploded view of a fluidic optical device similar to thatdepicted in FIG. 24.

FIG. 26 is a cross-sectional side view of a fluidic optical device witha compliant reservoir support and bladder, shown in an undeflectedstate.

FIG. 27 is a cross-sectional side view of a fluidic optical device witha compliant reservoir support and bladder, shown in a deflected state.

FIG. 28 is a cross-sectional view of an adaptive optical device having areservoir bladder.

FIG. 29 is a cross-sectional view of a fluidic optical device withsupport including a reservoir with open channels for control of fluidpressure.

FIG. 30 is an exploded view of a fluidic optical device similar to thatdepicted in FIG. 29.

FIG. 31 is a cross-sectional view of a portion of an electrowettingcapillary support.

FIG. 32 is a cross-sectional side view of a fluidic optical device withan edge support, external supports coupled to actuators, and compliantreservoir, shown in an undeflected state.

FIG. 33 is a cross-sectional side view of a fluidic optical device withan edge support, external supports coupled to actuators, and compliantreservoir, shown in a deflected state.

FIG. 34 is a cross-sectional side view of a fluidic optical device,including a gas pocket reservoir, shown in an undeflected state.

FIG. 35 is a cross-sectional side view of a fluidic optical device,including a gas pocket reservoir, shown in a deflected state.

FIG. 36 is a cross-sectional side view of a fluidic optical deviceconfigured for a pin-on-ring load.

FIG. 37 is a cross-sectional side view of a fluidic optical deviceconfigured for providing independent control of concentrated anddistributed loads on the optical surfaces.

FIG. 38 is a cross-sectional side view of an alternate embodiment of afluidic optical device configured for providing independent control ofconcentrated and distributed loads on the optical surfaces.

FIG. 39 is a cross-sectional side view of a fluidic optical device withan edge support, compliant reservoir, dual actuators and opticalsurfaces disposed below a rigid curved optical surface.

FIG. 40 is a cross-sectional side view of a fluidic optical device withthermally heated sealed compartments.

FIG. 41 is a magnified cross-sectional side view of a fluidic opticaldevice with thermally heated sealed compartments.

FIG. 42 is a three-dimensional view of a thermal heater disposed withinan optical element.

FIG. 43 is a cross-sectional side view of an adaptive fluidic opticaldevice including a diaphragm seal with optical surfaces in anundeflected state.

FIG. 44 is a cross-sectional side view of an adaptive fluidic opticaldevice with optical surfaces in a deflected state and bladder exhibitingdeflection in response to positive residual fluid pressure.

FIG. 45 is a cross-sectional side view of an adaptive fluidic opticaldevice with optical surfaces in a deflected state and bladdersexhibiting no deflection in response to zero residual fluid pressure.

FIG. 46 is a cross-sectional side view of an adaptive fluidic opticaldevice with optical surfaces in a deflected state and bladder exhibitingdeflection in response to negative residual fluid pressure.

FIG. 47 is a cross-sectional side view of a fluidic optical device withexternal supports and radially disposed bladder, shown in an undeflectedstate.

FIG. 48 is a cross-sectional side view of a fluidic optical device withexternal supports and radially disposed bladder, shown in a deflectedstate.

FIG. 49 is a cross-sectional side view of a fluidic optical device withexternal supports and axially disposed bladder, shown in a deflectedstate.

FIG. 50 is a cross-sectional side view of a fluidic optical device withexternal supports and radially disposed fluid channel.

FIG. 51 is a cross-sectional side view of an alternate configuration ofa fluidic optical device with external supports and radially disposedbladder.

FIG. 52 is a three-dimensional view of a fluidic optical device withactuation provided by an electromagnet actuator.

FIG. 53 is detailed three-dimensional view of a fluidic optical devicewith actuation provided by an electromagnet actuator.

FIG. 54 is an alternate detailed three-dimensional view of a fluidicoptical device with actuation provided by an electromagnet actuator.

FIG. 55 is a three-dimensional view of a fluidic optical device withactuation provided by a plurality of actuation members.

FIG. 56 is a three-dimensional cross-section view of an adaptive fluidicoptical device configured as a variable focal length cylindrical lens.

FIG. 57 is a detailed three-dimensional cross-section view of anadaptive fluidic optical device configured as a variable focal lengthcylindrical lens.

FIG. 58 is a partial cross-section view of an adaptive fluidic opticaldevice configured as a variable focal length cylindrical lens.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof, and in which is shownby way of illustration specific embodiments in which the invention maybe practiced. In this regard, directional terminology, such as “top,”“bottom,” “front,” “back,” “leading,” “trailing,” etc., is used withreference to the orientation of the figure(s) being described. Becausecomponents of embodiments of the present invention can be positioned ina number of different orientations, the directional terminology is usedfor purposes of illustration and is in no way limiting. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope of thepresent invention. The following detailed description, therefore, is notto be taken in a limiting sense, and the scope of the present inventionis defined by the appended claims.

Elements

In a preferred embodiment of the present invention, an adaptive fluidicdevice may comprise an adaptive fluidic lens. The adaptive fluidic lensmay include one or more compartment member (compartment). Thecompartment may function as the core or body of the lens through whichlight is transmitted and its propagation controlled. The compartment mayinclude and be at least partially bounded by one or more opticalsurface. One or more optical surfaces may be configured to elasticallydeform (or “deflect”) under an applied load. A fluid may be disposed atleast partially inside the compartment and in communication with anoptical surface. The compartment may include one or more support member(support), which may be configured to mount, fasten-to and/or provide aboundary condition for an optical surface and/or the compartment.Additionally, the support may serve to communicate an applied load to anoptical surface and/or the compartment, resulting in a change in anoptical property of the device. An actuator may be configured to providethe applied load (or “actuation force” or “motive force”). A housingmember (housing) may be provided and disposed in the proximity of thecompartment. The housing may serve to house, mount or contain and/orprovide structural support for the compartment and/or device or anymember thereof.

The Optical Axis

An optical axis may be associated with the device and defined as an axispassing through a portion of an optical surface. Preferably, the opticalaxis may be oriented orthogonal to and intersecting the center of anoptical surface. Throughout the following discussion, the use of theword “axial” may be used to mean: in a direction substantially parallelto the optical axis or cylindrical axis of the device.

The Clear Aperture

In the present embodiment, the device may further include a clearaperture. The clear aperture may preferably be configured in a circularshape, having a radius (clear aperture radius). However in otherconfigurations, the clear aperture may alternatively be configured inany other desirable shape (for example, rectangular). Preferably, theoptical properties of the device may be optimally utilized for lightincident on the clear aperture. The clear aperture may be disposedsubstantially concentric and orthogonal to the optical axis.Alternatively, the clear aperture may be disposed in any desirableorientation and/or position relative to the optical axis.

Clear Aperture Defined by Actuator or Device

In a present embodiment, the clear aperture may be defined or bounded byone or more components of the device; for example, features of thecompartment or actuator. In one example, the actuator may be aconfigured in the form of an annulus or annular disk (for instance, apiezoelectric ring bender). The inner diameter of the annular disk ofthe actuator (actuator aperture) may be disposed in opticalcommunication with an optical surface. In this fashion, the actuatoraperture may substantially define the clear aperture, since light raysnot passing through the actuator aperture may be substantiallyobstructed from impinging on the optical surface by the actuator.Similarly, the compartment, housing or any other portion of the devicemay include an aperture, edge, or other boundary disposed in opticalcommunication with an optical surface, thereby defining a clearaperture.

The Compartment Compartment as the Main Optical Body of the Device

The compartment may be considered to be an optical body of the deviceand configured for the transmission of light through it, reflection,diffraction or scatter of light off of it, and/or emission or absorptionof light by it. The compartment may include one or more optical surfacesand clear apertures.

Fluid Disposed in the Compartment Example of a Fluidic Lens

In a preferred embodiment, for example a fluidic lens, the compartmentmay be configured to contain one or more fluid. Preferably, the fluidmay be disposed in optical communication with a clear aperture.Alternatively, the fluid may be disposed in a fashion such that it isnot in communication with a clear aperture.

Fluidic Lens with Two Optical Surfaces

In this fashion, a ray of light may enter the compartment through aclear aperture of a first optical surface, propagate through a fluid andexit the compartment through a clear aperture of a second opticalsurface. In an alternate embodiment, a ray of light (or photon) mayenter the compartment through a first location on an optical surface,propagate through a media disposed in the compartment, and exit thecompartment through a second location on the optical surface. Examplesof such a configuration include: optical surfaces that are curved andintersect the optical axis at multiple locations; fluid or other mediadisposed in the compartment having waveguiding properties such asmetamaterials, transformational optics, or photonic crystals; ornonlinear optical materials such as those possessing suitablethird-order electric susceptibility and demonstrating the optical Kerreffect.

Fluidic Mirror

For example, in another embodiment, such as an adaptive or deformablemirror, the compartment may be bounded on a side by an at leastpartially reflective optical surface, for example, a mirror. In thisfashion, a compartment may contain a fluid and be bound on a side by anoptical surface. Light, external to the compartment may strike theoptical surface and at least a portion of the light may reflect off ofthe optical surface. Alternatively, light internal to the compartment,may strike the optical surface and at least a portion of the light mayreflect off of the optical surface. In general, such deformable mirrors,adaptive mirrors, or adaptive fluidic mirrors may be configured in anydesirable fashion to reflect and/or scatter light off of an opticalsurface (for example, the optical surface may include a mirror coating,diffractive grating, hologram, nanoparticles, or any other desirablesurface property).

Other Configurations of the Compartment

More generally, the compartment may be bounded by one or more opticalsurface such that a ray of light may be incident on the optical surfaceat two or more distinct locations. For instance, a ray of light mayenter the compartment through a first location on an optical surface andexit the compartment through a second location on the optical surface.In still other embodiments, for example, a mirrored fluidic lens, afirst optical surface may be at least partially transmissive while asecond optical surface may be at least partially reflective. In thisfashion, a ray of light may be transmitted through the first opticalsurface, into the fluid, reflect off of the second optical surface,propagate back through the fluid and exit the compartment through thefirst optical surface.

Reservoir Member of the Compartment

In yet other embodiments, the compartment may contain fluid disposedoutside of the clear aperture; in this fashion, at least a portion ofthe compartment may function as a reservoir for a portion of the fluid.

Closed or Open Compartment

The compartment may be closed or open to the external environment. Forexample, a closed compartment may contain a fluid and be hermeticallysealed from the external environment, while an open compartment maycontain a fluid and include one or more hole, via, duct, pass-through,port, channel or other opening. For example, channels may be disposed inthe compartment for providing communication of fluid or pressure betweenthe compartment and an externally disposed pump, actuator, otherreservoir, additional compartment or external environment.

Elastic Properties of the Compartment

The compartment may be at least partially compliant and/or rigid or beconfigured to exhibit any desired elastic or other physical, mechanical,optical, electrical or other properties.

Compression of the Compartment Due to Axial Force or Fluid Pressure

In one embodiment, a fluid-filled compartment may be configured todeflect in a compressive and/or tensile fashion in response to anapplied load. For example, an actuator may apply an axially-directedcompressive load to a compliant portion of the compartment. Theresulting compression of the compartment may result in a change in fluidpressure internal to the compartment and a redistribution of fluid inthe compartment. Likewise, the change in fluid pressure may bedistributed over the internal surface of the compartment, resulting in adeflection of an optical surface.

Compartment Actuated by Fluidic Pressure

Alternatively, the actuator may include a pump wherein fluid pressureinside the compartment may be adjusted by pumping fluid into and/or outof the compartment. One or more of the compartment and/or opticalsurface may deform or deflect in response to the change in fluidpressure. In one example of a fluidic lens, the compartment may besubstantially rigid, wherein a change in fluid pressure may result in adeflection of one or more optical surface, resulting in a change in anoptical property of the device.

Compartment as a Fluidic Prism

In another example, a fluidic prism, the compartment may be at leastpartially compliant and two optical surfaces may be substantially rigid.A change in fluid pressure may result in a deflection of thecompartment, but substantially no deflection of the optical surfaces.However, the deflection of the compartment may result in a change inrelative positions of the optical surfaces, and, hence, a change in apexangle of the fluidic prism.

Housing Member

In one embodiment a housing member (housing) may be provided anddisposed in the proximity of the compartment. The housing may serve tohouse the device and/or provide structural support for the compartmentand/or device or any members thereof. Further, the housing may includeor house a second compartment, actuator, support, optical surface,reservoir, or any other desirable element or member of the device.Further, the housing may be configured to provide electrical interfaceto actuators or other components in the device. Yet further, the housingmay include, house or provide first and/or second compartments,actuator, optical surface, reservoir actuators, mounts or fasteningfeatures, optical elements and/or any other desirable components of thedevice.

The Fluid

In a preferred embodiment, a fluid may be disposed at least partiallyinside a compartment. In other embodiments, for example, in the case ofa fluid disposed in a reservoir or pump disposed externally to thedevice, a fluid alternatively may be disposed outside of a compartment.

Multiple Fluids and Index of Refraction

More generally, one or more fluids or any other desirable media may bedisposed at least partially inside and/or outside of the compartment.Preferably, the fluid(s) or media on either side of an optical surfacemay be selected so that there is a difference in the index of refractionbetween the fluid or media disposed on one side of an optical surfaceand the fluid or media disposed on other side. In this fashion, a changein the shape profile of an optical surface may result in a change in aproperty of light transmitted across, or incident upon, the interface ofthe optical surface and a fluid, and hence, a change in an opticalproperty of the device.

Second Fluid

For example, a second fluid may be disposed in a housing or external (or“second”) compartment and/or in communication with a side of an opticalsurface. For example, a first side of an optical surface may be incommunication with a first fluid disposed in a first compartment. Asecond side of the optical surface may be in communication with a secondfluid disposed in a second compartment. Either or both compartments maybe disposed in one or more housing. Such configurations of multiplefluids and/or compartments may be employed to provide optical effectsincluding chromatic or dispersive optical properties, such as adaptivefluidic lens doublets or triplets. Alternatively, multiple fluids may bebalanced with similar densities or specific gravities in order to reduceor eliminate disturbances to the shape of the optical surface due togravitational forces.

Properties and Index Matching of the Fluids

First fluid, second fluid, or any other fluid may be index matched(e.g., matching indexes of refracting or impedance matched) to anyelement or component of the device or the environment external orinternal to the compartment. For example, first fluid may be indexmatched to a support over a selected range of wavelengths therebypreventing interference patterns and effects (such as etalons andNewton's rings) from occurring between a support and an optical surface.Further, the refractive index of a fluid may be matched to therefractive index of one or more optical surfaces to reduce reflectionlosses (or Fresnel reflections). In another embodiment the refractiveindex of the fluid may be selected to have a high refractive index tomaximize the dioptric range, the range of focal lengths, of a lensmember. The fluid may flow from one part of compartment 6404 to anotherwith little or no resistance. Further, a second fluid may havesubstantially the same or different index of refraction than the firstfluid. Further, the second fluid may be selected from any of the same ordifferent groups as that the first fluid. Yet further, first and secondfluids may be selected to have similar or generally identical densities,specific gravity, coefficient of thermal expansion, or any otherdesirable properties. For example, first and second fluids may bedisposed in respective compartments on either side of a single opticalsurface (or membrane). First fluid may be disposed in physicalcommunication with one side of an optical surface, while second fluidmay be disposed in physical communication with the other side of theoptical surface. In this fashion, the similar densities of first andsecond fluids may help balance the loading on either side of the opticalsurface due to gravity (for instance, when the optical axis ishorizontally oriented). Thus, gravity-associated deflections of theoptical surface and resulting optical aberrations of the device may bereduced. Further, the similar coefficients of thermal expansion of firstand second fluids may provide balanced loading of the optical surfacedue to gravity over an increased range of operating temperatures.

Compressibility of the Fluid

In a preferred embodiment, the fluid may be generally incompressible.However, in other embodiments (for example, configurations wherein oneof the fluids is a gas), it may desirable for a fluid to be at leastpartially compressible.

Properties of the Fluid

Preferably, the fluid may be at least partially transparent (ortransmissive) in a desired spectrum or range of electromagneticwavelengths. However, in other embodiments, the fluid may be selectedfrom known materials and have desirable characteristics of transmission,absorption, dispersion, specific gravity, coefficient of thermalexpansion, viscosity, vapor pressure, hydrophobicity, dielectricstrength, surface tension, electrical or thermal conductivity, or anyother desirable property. Further, the fluid may be selected from anyfluid, liquid, gas, gel, plasma, solid or vacuum or any other desirablemedia chosen for its performance characteristics including optical,mechanical, physical, electrical, chemical, or any other desirableproperties.

The Optical Surface

In a preferred embodiment of the present invention, the optical surfacemay be similar to one or more structures under the generalclassification of “plate” as understood in the field of plate theory (orplate deflection theory, continuum mechanics, mechanical engineering, orother related fields); such classifications include thick plates, mediumthickness (or Kirchhoff) plates, thin plates, and diaphragms (or“membranes”). These plate classes can be summarized briefly as follows:(a) Thick plates. The deflections of a thick plate are very small andtherefore fiber elongation and diaphragm stresses (which cause fiberelongation) may be ignored. However, as a result of the large thickness,the bending stresses are also small and therefore they are comparablewith shear stresses. The deflection of thick plates, therefore, is basedon bending and shear stress. The shear results in the distortion of theline segments perpendicular to the central plane of the plate; (b)Medium thickness plates (Kirchhoff plates). These plates have smallerthickness than thick plates, which results in higher bending stresseswhich prevail over the shear stress. Therefore the shear stresses may beignored as well as their result (i.e. distortion of the originallystraight perpendicular lines to the central plane of the plate). On theother hand, the deflection is not so big to result in a significantelongation of the fibers in the central plane (the plane dividing theplate in the middle of the thickness). Therefore diaphragm stress mayalso be ignored. Only the bending stress is considered for these plateswith linear distribution of the bending stresses along the platethickness and zero bending stress in the central plane of the plate. Anexample material that may be configured to exhibit properties similar toa medium-thickness plate includes flexible glass (or “microsheet”).Flexible glass may be approximately between 75 and 150 microns inthickness and present manufacturers of it include Corning Incorporated,Asahi Glass Co., Ltd., and Schott AG. One such commercially availableflexible glass is Gorilla® Glass manufactured by Corning Incorporatedhaving a Young's modulus of approximately 71.7 GPa; (c) Thin platesproducing large deflections. In the case of thin plates producing largedeflections, the effects of shear are even less significant than for themedium thickness plates and therefore its effects may be ignored.Bending stress must be taken into consideration and, in addition, thediaphragm (or “tension” or “tensile”) stresses also act and cannot beignored. This is due to the fact that there are larger deflections whichmay result in changes in the length of the central plane fibers. Theselength changes are related to the acting diaphragm stresses. Inaddition, this type of plate may be non-linear, i.e. deformations andstresses are not directly proportional to the loading, even if thelinear Hook principle applies. It is the so-called ‘geometricalnon-linearity’which results from high deformations—specifically as aresult of high turning angles. An example of a material that may beconfigured to exhibit properties of thin-plates may be the optical-gradeplastic, polycarbonate, having a Young's modulus of approximately 2 GPa;(d) Diaphragms (or “membranes”). Diaphragms are plates that may be sothin that their bending rigidity is negligible (as well as the bendingstress) and only tensile stress is considered (e.g. various elastomericmembranes). As a result of high deformations these plates are alsogeometrically non-linear. The optically-clear silicone,polydimethylsiloxane (PDMS), having a Young's modulus of approximately360-870 KPa, is an example of a material that may be configured in athin plate and/or diaphragm-like optical surface.

Properties of an Optical Surface

The optical surface may be configured to meet any characteristicproperties, for example, optical, physical, mechanical or any otherdesirable property or specification. Examples of such properties mayinclude: optical power, refractive index, dispersion, spectraltransmittance, diffraction, or any other desirable optical property;density, Young's modulus, Poisson's ratio, chemical composition,viscosity, glass transition temperature, coefficient of thermalexpansion, density, shear modulus, liquidus temperature, surfacetension, chemical durability, hydrolytic class, knoop hardness,grindability, strength, impact strength, coefficient of linear thermalexpansion, thermal conductivity, thermal diffusivity, specific thermalcapacity (heat capacity), specific heat, shore hardness, specificgravity, elongation, surface resistivity, volume resistivity, tensilemodulus, tensile strength, nominal strength at break, flexural modulus,flexural strength, impact strength, mold shrinkage, yield stress, waterabsorption, thickness, radius, width, length or any other dimensions. Inan embodiment, an optical surface may be substantially transparent atdesired wavelengths of light. However, in other embodiments, an opticalsurface may be reflective, diffractive, scattering, holographic or haveany other desirable optical property.

Boundary Conditions Governing the Shape of an Optical Surface

Generally, the shape and deflection characteristics of an opticalsurface disposed in communication with a support may be governed byphysical properties of the optical surface and/or support (such asYoung's modulus, thickness and length, width or radius of the opticalsurface and/or support), the applied load (such as fluid pressure;stresses or forces including bending moment, tensile or shear force orother forces), the state of deflection of the optical surface, support,and/or compartment, and/or other boundary conditions of the opticalsurface, support and/or compartment.

Bending of a Stiff Optical Surface

In one embodiment, a substantially stiff optical surface may be clampedor fixed, disposed in communication with, fastened by, or mounted to oneor more support. For example, a support may be fixed to the outer edgeof an optical surface. In one embodiment, the deflection of an opticalsurface may be dominated, or affected, by bending stress. As a result ofthe deflection of the optical surface being affected by bending stress,a bending moment may occur in the optical surface in response to anapplied load. A stiff optical surface may bend, substantially as aresult of an applied load, thereby changing certain optical propertiesof the device. Such a stiff optical surface may provide greaterresistance to disturbances (for example, gravity, shock or vibration)than more compliant, diaphragm-like optical surfaces.

Small and Large Deflections of the Optical Surface and Restoring Forces

In a preferred embodiment of the present invention, an optical surfacemay be configured for deflection, in response to an applied load, basedsubstantially on bending, tensile, compressive or any other desirablestress. Likewise, upon removal or reduction of the applied load, theoptical surface may substantially recover or tend toward its undeflectedshape primarily due to a restoring stress. In some embodiments, theoptical surface may be configured for small deflections (i.e., where themagnitude of deflection is approximately smaller than the thickness ofthe optical surface); for example; Kirchhoff or thin plate-like opticalsurfaces. Alternatively, in other embodiments, the optical surface maybe configured for large deflections (i.e., where the magnitude ofdeflection is approximately greater than the thickness of the opticalsurface); for example, diaphragm-like optical surfaces where strain maybe dominated by elongation of radial fibers. In general, any type ofoptical surface may be configured for small, large, or any otherdesirable type of deflection. Additionally, the optical surface may bepreferably, configured for deflection or strain within its elasticlimit. For example, an actuator may apply a load to at least a portionof the compartment, optical surface, support or any other part of thedevice, resulting in a deformation of at least a portion of the opticalsurface. The applied load may be in the form of uniform and/orconcentrated load. Upon the removal of the applied load, the stiffnessof the deflected optical surface may provide a restoring force,assisting the device in returning the optical surface substantially toits undeflected state.

Diaphragm-Like Optical Surface

In other embodiments, an optical surface may be diaphragm-like, similarto a membrane, wherein its deflection may be dominated or affected bydiaphragm, tensile or other stresses resulting in a “stretching”deformation of the optical surface. More generally, the deflection of anoptical surface may be dominated or affected by any combination ofstresses, for example, tensile, diaphragm, bending and/or any otherdesirable stress.

Rigid Optical Surfaces

In some embodiments, one or more of the optical surfaces may be at leastpartially rigid. In this fashion, a rigid (or “static”) optical surfacemay be configured to exhibit substantially zero deflection in responseto the same or similar applied load that may be utilized to cause thedeflection of a compliant, or non-rigid, optical surface. For example,in one embodiment, a plano-convex adaptive fluidic lens may incorporateone compliant (or deflectable) optical surface and one rigid planaroptical surface. Both optical surfaces may be subjected to the sameapplied load, however, only the compliant optical surface may deflectunder the load. In this fashion, the compliant optical surface maydeflect in a convex shape, changing radius of curvature and/or otheroptical properties, as a function of the applied load, while the rigidoptical surface may remain planar regardless of the state of the appliedload. The rigid optical surface may comprise optical elements such as aglass or plastic element, optical window, lens, prism, mirror or anyother desirable optical element. Alternatively, an optical surface maybe configured with any desirable shape or profile in its deflected orundeflected state. For example, a rigid optical surface may beconfigured with a static convex profile. Further by way of example, adeflectable optical surface may have a convex shape while in anundeflected state, and a planar or altered convex shape while in adeflected state.

Optical Surface May Include Metamaterials

In other embodiments, an optical surface, fluid or other component ofthe device may include metamaterials, photonic crystals, nanoparticlesand/or be configured to support surface plasmons, guided waves or otheroptical propagation modes.

Shape of the Undeflected Optical Surface

In the present embodiment, an optical surface (i.e., either adeflectable or undeflectable optical surface) may be configured to beplanar and circular in shape; however, any other desirable shape (suchas rectangular, elliptical, annular, etc.) may be employed. For example,rectangular-shaped optical surfaces may be employed in order to enable afluidic optical device with variable astigmatism, or provide a variablefocal-length cylindrical lens. Further, the undeflected shape of theoptical surface may be non-planar. For example, an adaptive fluidic lensmay incorporate an optical surface that has been molded in a convexspherical cap having a radius of curvature. In response to an appliedload, the optical surface may change its radius of curvature, therebychanging an optical property of the device.

Pre-Tensioned Optical Surfaces

In some applications (for example, see U.S. patent application Ser. No.12/706,637, to Robert G. Batchko et al., entitled “FLUIDIC LENS WITHREDUCED OPTICAL ABERRATION”, filed Feb. 16, 2010, which has beenincorporated herein by reference) it may be desirable to pre-tension anoptical surface (for example, during assembly of a fluidic opticaldevice). Pre-tensioning of the optical surface may increase the fluidpressure required to achieve a given curvature, thereby making thefluidic optical device less susceptible to optical aberrations due togravity or other disturbances. Further, pre-tensioning an opticalsurface may help reduce its response time (i.e., the time required toachieve a stable state of deflection in response to a change in appliedload. Preferably, optical surfaces having diaphragm-plate-like materialproperties or low modulus of elasticity may incorporate pre-tensioning.However, other types of optical surfaces, including thin plate,medium-thickness plate, thick plate, or any other desirable type ofoptical surface may be pre-tensioned.

Angle Between Two Optical Surfaces

In a preferred embodiment, two optical surfaces may bound two sides of acompartment and may be disposed substantially parallel to each other.However, in other applications it may be desirable for the opticalsurfaces to be configured at any desirable relative position withrespect to each other and/or the compartment. For example, two rigidoptical surfaces may be disposed at an acute angle relative to eachother. Such a configuration may be desirable for a fluidic prism or beamscanner wherein the angle between the optical surfaces may be controlledby an applied load. In general, an optical surface may be configured inany desirable orientation relative to the optical axis, other opticalsurfaces, the compartment, and/or other part of the device.

The Actuator Function of Actuator and Configuration of Applied Load

The actuator may serve to provide the applied load (or “load”,“actuation force” or “motive force”) that may be communicated to, andresult in the deflection of, a compartment, support and/or an opticalsurface. In a preferred embodiment, the load may be connected from theactuator to an optical surface through one or more of the compartmentand/or support. The actuator may be configured to deliver the appliedload in any desirable fashion, for example: a bending moment,concentrated load, concentric load, point load, distributed load,uniformly distributed load, fluid pressure, shear load, shear stress,surface stress (such as a radial stress or a tangential stress), stressnormal to or at any angle to the optical axis, other forms of loadingsimilar to those associated with the deflection of beams, plates ordiaphragms, or any other desirable form of loading. Further, the loadmay be converted or modified in any desirable fashion, for example:amplification, conversion between stroke, rotation, pressure and/ormoment modification, or any other conversion or modification of anydesirable types of force or load. In one embodiment, the actuation forcemay be applied to a portion of the compartment and/or support, resultingin a concentrated and/or distributed load being applied to the support.The applied load may result in a deformation of the support and amovement or deflection of an optical surface.

Types of Actuators

In a preferred embodiment, the actuator may include an electromagnet andmay provide tensile and/or compressive force. In another embodiment theactuator may include one or more piezoelectric ring bender (ringbender). As described in U.S. patent application Ser. No. 12/706,637, toRobert G. Batchko et al., entitled “FLUIDIC LENS WITH REDUCED OPTICALABERRATION”, filed Feb. 16, 2010, the entire contents of which have beenincorporated herein by reference, in one embodiment, an actuator may beformed in the shape of a substantially flat ring or annulus (or annulardisk) and may include an aperture; for example, a ring bender. Uponactuation, the ring bender may provide an axially directed (or directedparallel to the optical axis) load. In other embodiments, any known typeof actuator may utilized, including, for example, any of the following:electrostatic actuators; voice coils; solenoids; piezoelectric;piezoceramic; electroded piezoceramic ring actuators; electrostrictive;shape memory; shape memory alloy; dielectric electroactive polymer;dielectric polymer; electroactive polymer; multi-layer (or stackedlayers of) dielectric or electroactive polymer; conductiveelectro-active polymer; shape memory alloy (SMA) actuators;electroactive polymer artificial muscle (EPAM) actuators; resonantmotors; resonant piezoelectric motors; ultrasonic motors; ultrasonicpiezoelectric motors; elliptical path motors; precessing motors; steppermotors; stepper motors combined with a mechanism for conversion ofrotary into linear motion (i.e., such as a lead screw arrangement);other types of motor actuators; other types of piezoelectric actuators(i.e., such as flextensional, recurve; pre-stressed; multilayer;bimorph; unimorph; piezoelectric disk benders; piezoelectric ringbenders; piezoelectric tube; piezoelectric sphere or spherical sector;piezoelectric c-block; piezoelectric multilayer stack; piezoelectricrings, etc.); and piezoelectric tubes combined in telescopicarrangements to multiply their axial stroke by the number of telescopingsegments. In order to gain additional actuation amplitude (or “stroke”)and/or additional actuation force, a plurality of actuators may becombined or stacked before being brought into contact with thecompartment and/or any other element of the device. In general, anydesirable type of actuator or actuators may be employed to provide theapplied load.

Alternate Configurations and Shapes of Actuators; Pumps

In alternative embodiments, the actuator may be formed in any desirableshape and may or may not include an aperture in communication with theclear aperture. In a preferred embodiment, the actuator may be disposedin communication with or proximal to an optical surface or thecompartment. Alternatively, the actuator may be disposed apart from theoptical surface(s) and/or compartment. For example the actuator mayinclude a fluid pump located a distance away from the optical surfaceand/or compartment. As is well known in the art, the actuation forceprovided by a pump actuator may serve to adjust fluid pressure in thecompartment, thereby providing an applied load in the form of adistributed load to one or more of an optical surface, support and/orcompartment and resulting in a change in an optical property of thedevice.

Stacks of Bender Actuators

In another embodiment, a plurality of actuators, such as piezoelectricring benders, may be configured in communication with each other. Suchconfigurations may include a stack of ring benders whereby the stackingprovides an enhancement or modification in one or more of force, stroke,stiffness, compliance, speed, range of operating temperatures, or anyother desirable parameter of actuators. For a stack of actuators, eachindividual actuator in the stack may have a plurality of electricalterminals or electrodes. Interconnects may be employed to makeconnections between electrodes of actuators in the stack. Forpiezoelectric ring benders (ring benders) may have a metal shimelectrode and a conductively-coated ceramic electrode. In one exampleconfiguration, conductive spacer rings may be employed between each ringbender in the stack to connect the shim electrode of one to the ceramicelectrode of the next one in the stack. Additionally, conductive strapsmay be employed at the inner and/or outer edges of the ring benders toconnect electrodes of adjacent actuators in the stack as desired.

Direction of Actuation Force and Types of Stresses

In one embodiment, the actuation force may be directed substantiallyparallel to the optical axis, and deliver axial stress to the one ormore of the compartment, support and/or optical surface. However, inother embodiments, the actuation force may be exerted in any desirableorientation, for example, in a radial, tangential, orthogonal or anyother orientation relative to the optical axis. For example, in anotherembodiment, the actuator and/or actuation force may be distributedgenerally around the one or more of compartment, support and/or opticalsurface. The actuator may thus be configured to deliver one or more of aradial stress, tangential stress, circumferential stress or hoop stressto one or more the compartment, support, optical surface or any othermember of the device.

The Support Functions of the Support

In one embodiment, one or more supports may be disposed in communicationwith one or more of a compartment and/or an optical surface. (Note,throughout this discussion, the terms “support” and “restraint” may beused interchangeably with the same meaning). The support may providemultiple functions in the device. In one function, the support may besimilar to supports or connectors known in the field of mechanics,wherein a support provides the interface for communicating loads and/orforces to objects or structures, for example, a beam, cantilever, plate,bridge, etc. In this fashion, the support may serve to mount a portion(for example, the edge) of an optical surface to a portion of thecompartment. In this capacity, the support may provide a boundarycondition for an optical surface, thereby affecting the shape profile ofthe optical surface as it deflects in response to the applied load. Forexample, the optical surface may be substantially stiff and itsdeflection dominated or affected by bending stress. The support may besubstantially rigid, clamping the outer edge of the optical surface(such support may be similar to a fixed or clamped support of a plate orbeam). Such a support may cause the optical surface to bend or undergotensile, bending or other stress or strain under an applied load. As analternative example, the support may be at least partially compliant,providing at least a partially flexural or hinge-like boundary conditionto the optical surface (such support may be similar to a fulcrum, hinge,rocker, pin, pin-joint or simple support of a plate or beam). Such acompliant support may allow the optical surface to at least partiallypivot, slide, bend or other deflection and/or undergo tensile, bendingor other stress or strain under the applied load. Alternatively, thesupport may be compliant to pivoting but not compression, as may be thecase for a hinge or flexure. In general, the support may be configuredto support or mount the optical surface in any desirable fashion.

Shapes of Support and Support Radius

In one embodiment, the support may be circular ring-shaped and theoptical surface may be circular disk-shaped. The support may have aradius (support radius) approximately equal to or smaller than theradius of edge (or “outer edge”) of the optical surface (optical surfaceradius). In one embodiment, the inner diameter (or inner perimeter orinner edge) of a support may substantially define the perimeter of theclear aperture. In other embodiments, the support may have any desirableshape, including square, oval, rectangular, open or closed shapes(including lines, segments, L-shaped sections), asymmetric or any otherknown shape. Alternatively, the outer edge of the optical surface mayextend radially outward past (or “overhang”) a support. In general, asupport may be disposed anywhere on an optical surface.

A Support as a Distinct or Integrated Component

The support may be a distinct component in the device, or alternatively,it may be integrated (or unitary or monolithic) with one or more of theoptical surfaces, or any other desirable element of the device.

A Compliant Support and Restoration Forces

In an embodiment, the support may be configured to be at least partiallycompliant. The compliance of the support may allow the compartment to becompressed, tensioned, torqued or otherwise elastically deformed inresponse to a load from an actuator. In one embodiment, such adeformation of the support may result in a change in fluid pressureinternal or external to the compartment. Such change in fluid pressuremay be employed to provide an applied load (such as a uniformlydistributed load) to an optical surface, resulting in a deflection ofthe optical surface. For example, in one embodiment, a majority of thereaction force may be provided by the support with the balance ofreaction forces coming from the optical surface. Alternatively, any partof the device may deform in response to the applied load. The elasticenergy of one or more of the deformed support, optical surface, fluid,compartment, or any other part of the device may contribute a restoringor reaction force any of these components.

Support in Communication with Optical Surface; Properties of the Support

Properties of the support may include material properties (such asmodulus of elasticity), geometric properties (such as shape),dimensional properties (such as relative thickness, diameter, width orlength), boundary conditions, magnitude of loading or other propertiesor conditions. Further, the fashion in which the support is fastened toor disposed in communication with the optical surface and/or compartmentmay affect the deflection of the optical surface. For example, thesupport may be similar to a fixed, clamped, compliant, cantilever,sliding, hinge, simple, ring, pin-joint, or any other desirable type ofsupport similar to those known in the field of mechanics, plate and/orshell theory. Additionally, the support may be at least partially rigidand/or elastic (or compliant) and have any desirable geometric, materialor other properties. Techniques for fastening, or disposing, a supportin communication with an optical surface, compartment or any otherdesirable part of the device may include adhesive bonding with orwithout specialized surface treatments (such as exposure to oxygenplasma prior to making contact between the parts that are to be bonded),clamping, bonding, molding, use of frictional, interference or othertypes of fit, and/or any other desirable methods of fixturing.

Bonding of Support to Optical Surface

In another embodiment, the inner support (or “inner restraint”) may bedisposed in communication with one or more of the optical surfaces. Theinner restraint and one or more of the optical surfaces may be fixed toeach other (for example, by way of a chemical bond (such as adhesion),mechanically clamping, or a frictional or interference fit).

Support Provides a Seal for the Compartment

In another function, the support may be disposed in communication with aportion of an optical surface and/or the compartment and provide a sealfor containing fluid, solid, gas and/or any other desirable media inand/or out of the compartment. Alternatively, a support may beconfigured to substantially create a seal between two optical surfaces.Alternatively still, the support may form a boundary between a firstportion of the compartment disposed radially internal to the support(inner sub-compartment), and a second portion of the compartmentdisposed radially external to the support (outer sub-compartment). Inthis fashion, the support may be configured to control, prevent or limitfluid communication between the two portions of the compartment. Moregenerally, the support may provide a seal for containing fluid, solid,gas and/or any other desirable media in and/or out of any portion of thecompartment. In an embodiment, the inner sub-compartment may be similarto a clear aperture. Further, the outer sub-compartment may be similarto a reservoir.

Fluid Channels in a Support

In one embodiment, it may be desirable for one or more of thecompartment and/or a support to be configured to permit fluid flow orfluid communication between different regions of the compartment. Suchfluid communication may be desirable, for example, for the control offluid pressure in the compartment. To facilitate such fluidcommunication, a ring-shaped support may be configured with one or moreopenings (or holes, vias, ducts, pass-throughs, ports or channels)adapted to provide fluid communication between the regions of thecompartment separated by the support. In one embodiment, channels may bedisposed radially in the support. Alternatively, the channels may bedisposed axially or in any other desirable fashion in the support. Inthis fashion, such fluid flow may serve to make fluid pressure moreuniform throughout the compartment. Additionally, fluid flow in suchchannels may be employed to reduce changes in fluid pressure in thecompartment. In one example configuration, a compartment may beconfigured with two concentric ring-shaped supports disposed between twosimilar circular-disk optical surfaces. The first ring-shaped supportmay be disposed near the edges of the optical surfaces, and the secondring-shaped support may be disposed at a radius smaller than that of theedges. The second support may be configured with radial channels toprovide fluid flow through the second support. For example, byconfiguring the second support with radial holes, fluid may flow betweena region of the compartment having a radius smaller than the secondsupport radius and a region of the compartment have a radius larger thanthe second support radius.

Rounded Surface of the Support

In a preferred embodiment, a support may include one or more surfacesconfigured to contact an optical surface (support contact surface). Asupport contact surface may be shaped in a fashion to minimize thesurface area of the optical surface in contact with the support. Forexample, a support contact surface may include rounded surface regionswherein a cross-section of the support may be substantially circular inshape. Such minimization of contact area between the optical surface andthe support may allow the support to function more similarly to afulcrum (or simple support), facilitating smooth bending (or deflection)and/or pivoting of the optical surface about the support. Alternatively,the cross-section of the support may be formed in any other desirableshape (for example, square or triangular in cross-section).

Restoring Forces of the Support

As is well known in the art (for example, by the Poisson effect), when amaterial is compressed in one direction, it may tend to expand in theother two orthogonal directions perpendicular to the direction ofcompression. In one embodiment, the support may be disposed in aring-shape and comprise at least a portion of a sidewall of thecompartment. Further, the support may be configured such that when it isdriven into axial compression, it may also expand radially toward theinside of the compartment (or toward the optical axis). Suchradially-inward expansion of the support may further increase fluidpressure in the compartment, thereby enhancing the deflection of theoptical surface and one or more optical property of the device. Ingeneral, a compliant support may be configured as any desirable part ofthe compartment, wherein a deformation of the support, in response to amotive force, may result in a change in fluid pressure internal and/orexternal to the compartment. Further, due to the specific geometry ofthe support, such deformation of the support may result in anamplification or de-amplification of such fluid pressure.

Support Mounted Between Two Optical Surfaces

In one embodiment, a support may be disposed between, a first opticalsurface and a second optical surface. The support may be configuredsubstantially in the shape of a circular ring. Further, at least aportion of the support may be substantially rigid and configured tofunction as a simple support, or fulcrum. An applied load may bedelivered to first and/or second optical surface by means of aconcentrated, distributed or other load. The applied load may beconfigured in such a fashion that one or both of the optical surfacesdeflect toward the support. For example, negative fluid pressure in thecompartment may cause an optical surface to deflect toward the support.Alternatively, a load applied to an optical surface, at a radiusdifferent from the support radius, and in a direction toward thesupport, may cause the optical surface to deflect toward the support. Inthis fashion, the support may provide a reaction force, in response tothe applied load, to the deflected optical surface. Alternatively, bothfirst and second optical surfaces may deflect toward the support,wherein the support may provide a reaction force opposing the deflectionof both optical surfaces.

Projections—Positioning Features in the Second Support

In another embodiment, a support may include radial features foraccurately positioning it within the compartment. In one embodiment,such positioning features may include spoke-like projections(“projections”, or “spider”), the distal ends of which may be disposedin communication with a boundary of the compartment (for example,another support, optical surface, sidewall or other part of thecompartment). Such projections may function to help accurately positionthe support at a desired location relative to the optical axis.Alternatively, the positioning features may be shaped or configured inany desirable fashion. In one embodiment, the projections may be atleast partially compliant and include features similar to slides,flexures and/or hinges. For example, a projection may be configured toallow the support to be displaced along the optical axis whilemaintaining its radial position in the compartment.

Deflection of an Optical Surface Aspheric Curvature of the OpticalSurface Due to a Distributed Load

In some configurations, for example, wherein an optical surface may bedisposed in communication with a support and deflected by a distributedapplied load (such as fluid pressure), the optical surface may deflectwith an aspheric curvature. Further, such aspheric curvature maydeleteriously affect the curvature of the optical surface in the clearaperture. Likewise, aspheric curvature may be exhibited in deflectedoptical surfaces clamped to a support where the applied load isdistributed and/or concentrated (such as ring-on-ring, concentric orpin-on-ring). Further, aspheric curvature may persist in configurationswherein the support imparts no bending moment on the optical surface,and/or wherein the deflection of the optical surface may be dominated bybending, diaphragm, tensile or other stress. Such aspheric curvature inthe clear aperture of the optical surface may lead to optical propertiesof the device, such as unwanted aberrations. Therefore, in someapplications, it may be desirable to have the ability to control suchaspheric curvature, and, hence, related optical properties.

Lens Vertex and Vertex Curvature

In some embodiments, a deflected optical surface may exhibit a vertex.As understood in the field of optics, a vertex may be the point on theoptical surface that intersects the optical axis. Further, the vertexmay exhibit a curvature (vertex curvature). For example, by convention,in a convex deflected optical surface, the vertex curvature may bepositive. Likewise, a concave deflected optical surface may have anegative vertex curvature. In a preferred embodiment, a vertex may belocated in the proximity of the optical axis, or near the center of theclear aperture of the lens. Alternatively, the device may be configuredsuch that a vertex is located at other locations on the optical surface(for example, an adaptive fluidic lens with coma aberration).Alternatively still, an optical surface of a fluidic prism or beamscanner may be substantially planar and not exhibit a vertex at all.Generally, an adaptive fluidic lens may be configured such that thevertex curvature ranges from positive to negative values throughout therange of deflection of the optical surface. The deflection of an opticalsurface may be characterized by the “height” of the vertex (or thedistance from the vertex on a deflected optical surface to thecorresponding point on the optical surface in an undeflected state). Insome embodiments, actuation of an adaptive fluidic device may result ina deflection of an optical surface of the device, and a correspondingchange in height of the vertex of the optical surface.

Support Curvature

In an embodiment, a circular stiff optical surface may be clamped in theproximity of its edge by a fixed, ring-shaped support. The radius of thesupport (support radius) may be approximately equal to the radius of theouter edge of the optical surface (edge radius). Likewise, a support mayclamp the optical surface at a radius other than the edge radius. Insuch configurations, in addition to vertex curvature described above,the deflected optical surface may exhibit a second, annular-shapedregion of curvature (support curvature), which may occur in a regionnear the support.

Support Curvature and Vertex Curvature May have Opposite Sign

The support curvature may result from the clamping (or restraining) ofthe deflected optical surface by the support. (Stated differently, theclamped support may impose a bending moment on a deflected opticalsurface). Further, as a result of the optical surface being restrainedat the support radius, and the vertex being unrestrained (for example,at the center of the optical surface), the sign of the support curvature(as measured along a radius of the optical surface) may generally beopposite in sign to that of the vertex curvature. For example, adeflected optical surface under a positive fluid pressure applied loadmay exhibit a positive vertex curvature and negative support curvature.In general, any desirable configuration of applied load, optical surfaceand/or clamped support may be selected. Alternatively, optical surfacesor supports having rectangular, elliptical or any desirable shape,homogeneous or inhomogeneous material properties, or having uniform ornon-uniform thickness may be employed. Likewise, a device may beconfigured wherein one or more regions of positive and/or negativecurvature may be disposed at generally at any desirable locations on anoptical surface (for example, an adaptive fluidic wavefront correctormay include a plurality of concentric ring-shaped supports wherein itsoptical surface may include a plurality of zones of alternating sign ofcurvature).

Inflection Point Cause and Definition of Inflection Point

As a result of the vertex curvature and support curvature havingopposite sign, a stiff deflected optical surface may exhibit a region ofinflection (“inflection” or “contraflexure”) in curvature (as measuredalong a radius of the optical surface). As understood in the field ofdifferential calculus, an inflection may be defined as a point on acurve at which the curvature changes sign. In this fashion, the radiusof the inflection (inflection radius) may typically occur in an annularregion of the optical surface greater than the vertex and smaller thanthe edge radius. (Note, the locus of points constituting an inflectionmay sometimes be referred to as an “inflection point” in regards to theradial location of the inflection in the curvature of the opticalsurface).

Inflection Leads to Asphericity and the Need for a Spherical Curvaturein the Clear Aperture

In some applications, it may be desirable for the clear aperture of theoptical surface to maintain a substantially spherical shape throughoutat least a portion of its states of deflection. However, the existenceof an inflection may result in undesirable aspheric contributions to theshape of the optical surface.

Reduction of Curvature and Aberrations by Pivoting Support

Deleterious optical effects associated with an inflection (for exampleundesirable aspheric curvature in the clear aperture) may be diminishedby configuring the device such that the inflection radius is madesubstantially larger than the clear aperture radius, or the inflectionis eliminated altogether. Such an increase in inflection radius, orelimination of inflection, may be accomplished by reducing the supportcurvature. In this fashion, an optical surface that is allowed to pivotabout the support may exhibit a reduced magnitude of support curvature.Likewise, the reduction of support curvature will cause the infectionradius to increase toward the edge of the optical surface. In the caseof an optical surface being completely free to pivot without restraintfrom the support, the inflection radius may be substantially made equalto the edge radius, resulting in the elimination of inflection. In oneembodiment, the optical surface may be allowed to pivot by configuringthe support with sufficient compliance. Alternatively, a rigid supportmay be configured to function similarly to a fulcrum or simple support,allowing the optical surface to pivot. In this fashion, the inflectionradius may be expanded and the optical surface may exhibit a morespherical profile (in regions, for example, near or inside the clearaperture) throughout at least a portion of its states of deflection. Ingeneral, the elastic modulus, shape and/or dimensions of the opticalsurface and/or support, load and/or other properties of the device, maybe selected in any fashion to modify the inflection as desired.Generally, the inflection may be disposed generally at any desirablelocation(s) on the optical surface, including at radial locationsinternal or external to the clear aperture radius.

Controlling the Inflection

In certain applications it may be desirable for an inflection radius tobe generally fixed throughout all states of deflection of an opticalsurface. However, in other embodiments such as adaptive fluidic lenseshaving variable aspheric correction, it may be desirable for the radiallocation or other properties of the inflection to be adjustable. Foreither case, the inflection radius may be affected dynamically duringoperation of the device by several approaches. For example, the supportmay be configured with adjustable compliance, rigidity, torque or otherproperties, and those properties may be controlled during actuation ofthe device. For example, elastic modulus, thickness, radius, width,length and/or other dimensions of the optical surface and/or support, orany other parameters of the device may be chosen. In this fashion, thepivot angle of the optical surface at the edge radius may be controlled,thereby controlling the inflection radius. In one embodiment, forexample, a deflected optical surface may exhibit a given vertexcurvature. A support, or plurality of supports, may be configured withan actuator for controlling the pivot angle of the optical surface inthe proximity of the support. In this fashion, the pivot angle may beincreased, thereby resulting in an increase in the inflection radius.Likewise, the pivot angle may be decreased to reduce the inflectionradius. Alternatively, the inflection radius may be controlled by theuse of multiple applied loads. For example, a concentrated ring-on-ringload may be applied to produce the primary deflection, or curvature, ofthe optical surface. Additionally, a fluid pressure or distributed loadmay be applied to control the inflection radius. Such active control ofthe inflection radius may enable control of the aspheric contribution tothe curvature, and the deflection in general, of the optical surface.The ability to control both the spherical and aspheric curvaturecharacteristics of an optical surface may be desirable in certainapplications.

Persistence of Inflection

In certain configurations, the optical surface may only have a limitedability to pivot (for example, the support may have an insufficientlylow modulus of elasticity). In such cases, the inflection radius may beincreased to a value greater than the clear aperture radius, but suchincrease still may not be sufficient to eliminate the effects ofaspheric curvature from entering the clear aperture of the opticalsurface.

Preferred Embodiment Ring-on-Ring Load and Stiff Optical Surface

In a preferred embodiment, spherical curvature may be maintained in theclear aperture region of the optical surface throughout its states ofdeflection by the use of a stiff optical surface and concentratedconcentric ring-on-ring (or “double-ring”) applied load. In one exampleof such a configuration, a compartment may be bounded by a first opticalsurface and a second optical surface. One or more of first and secondoptical surfaces may be capable of deflection by bending. Further, firstand second optical surfaces may be circular-disk shaped and havesubstantially the same edge radius. A first ring-shaped support (firstsupport) may be configured with a first support radius substantiallyequal to, or slightly smaller than the edge radius. The first supportmay be fastened to first and second optical surfaces and may form aseal. First support may be at least partially compliant and configuredto allow first and/or second optical surfaces to pivot. The compartmentmay thus be bounded around its perimeter by first support. Optionally,one or more sidewall members, plate members, sidewall support members orany other additional desired members may optionally be provided tofurther bound and seal the compartment. A fluid may be disposed in thecompartment. A substantially rigid second ring-shaped support (secondsupport) may be disposed concentric to first support. Further, secondsupport may be disposed in communication with first and second opticalsurfaces in a fashion similar to a simple support. A clear aperture maybe provided and have a clear aperture radius approximately equal to orsmaller than the second support radius. An optical axis of the devicemay be provided and disposed substantially normal and concentric tofirst and second optical surfaces and first and second supports. Thecompartment and one or more actuator may be disposed in a housing. Theactuator may be annular disk-shaped and configured to deliver aconcentrated ring load (applied load) to the compartment. The radius ofthe applied load may be approximately equal to the first support radius.In one configuration, a first actuator may be disposed in communicationwith first optical surface. Likewise, a second actuator may be disposedin communication with second optical surface. Optional ring-shapedconnectors (connectors) may be disposed between optical surfaces andactuators. Further, connectors may be at least partially compliant andprovide an interface for delivering the applied load. Alternatively,actuators may be directly bonded, deposited, coated or fastened in anydesirable fashion in communication with optical surfaces. The appliedload may be directed parallel to the optical axis and configured toprovide a compressive force to the first support. Under a first state ofactuation, first support may not be compressed and optical surfaces maybe substantially planar. Under a second state of actuation, firstsupport may be in a state of axial compression. In this fashion,actuators may communicate the applied load to optical surfaces,resulting in the compression of first support and displacement of theedge of one or more of optical surfaces. Likewise, the rigidsimple-support provided by second support may provide a reaction force,resulting in the bending deflection of at least one of optical surfaces.In alternative embodiments, the roles of the supports and forces may bereversed. For example, one or more second supports may communicate theapplied load while one or more first supports may provide the reactionforce. In general, any desirable configuration of applied and reactionloads and forces may be employed. Although first support may besubstantially compliant, such compliance may be imperfect whereinoptical surfaces are not perfectly free to pivot. In such case, firstsupport may still impose a bending moment on optical surfaces, whereinsuch bending moment may result in an inflection. However, due to theability of optical surfaces to substantially freely pivot about secondsupport radius, second support may not impose a bending moment onoptical surfaces. Due to the lack of a bending moment at second supportradius, the inflection radius may be restricted to a range ofapproximately greater than the edge radius and smaller than the secondsupport radius. Further, the lack of a bending moment at second supportradius may serve to substantially isolate aspheric curvature to radiiapproximately greater than second support radius. As a result, deflectedoptical surfaces may exhibit a vertex in clear aperture while thecurvature of deflected optical surfaces in clear aperture may besubstantially spherical. In alternative embodiments, optical surfaces,supports, compartment, actuators, housing and any other part of thedevices may be configured in any desirable shape. In one embodiment, thedevice may be preferably configured with substantially mirror symmetryabout a mid-plane of the compartment normal to the optical axis. In thisfashion, optical surfaces may deflect with mirror symmetry.

In another embodiment one optical surface may be configured to besubstantially rigid and undergo substantially no deflection in responseto the applied load (for example, rigid optical surface may be similarto a thick optical window or thick plate). In general, either opticalsurface may similar to one or more of a medium-thickness plate,Kirchhoff plate, thin plate, or diaphragm plate.

Residual Fluid Pressure

In the present embodiment the compartment may be sealed such that fluidcannot substantially enter or escape from it. Additionally, in thepresent embodiment, one or more of the first optical surface, secondoptical surface, first support, second support, compartment, or anyother member of the device, may be configured to deflect or change inshape under an applied load. In some configurations, such deflectionsmay result in a net imbalance in the change in pressures among regionsof the compartment. For example, a region of the compartment at radiigenerally smaller than the clear aperture radius (“first compartmentregion”, or “inner sub-compartment”) may increase in volume as portionsof the device (for example, the optical surfaces or support) deflect.Likewise, an annular region of the compartment bound by the edge radiusand clear aperture radius (“second compartment region” or “outersub-compartment”) may undergo a decrease in volume as portions of thedevice deflect. In some cases, the net change in volumes of thecompartment regions may not completely balance (i.e., sum to zero). As aresult of such a net volume imbalance in the compartment, a residualfluid pressure (or “pressure excursion”) may be result and be appliedsubstantially uniformly throughout the compartment. Such residual fluidpressure may result in an applied distributed load causing the firstand/or second optical surface to undergo a residual deflection. Suchresidual deflection, being a result of residual fluid pressure mayresult in aspheric contributions to the total deflected shape of thefirst and/or second optical surface, which, in some cases, may beundesirable.

Methods of Controlling Residual Fluid Pressure

As described above, adaptive fluidic devices which achieve modulation oftheir optical properties (for example, focal power) by bending of theoptical surfaces bounding may be subject to spherical and otheraberrations which are dependent on residual fluid pressure, internal tothe compartment. To achieve a sufficiently low residual fluid pressure,or control over the residual fluid pressure, several techniques may beemployed. For example, the radii of inner and edge supports may betailored. Further, the compartment may be connected to external,compliant-wall reservoirs. Such compliant reservoirs may havesubstantially greater compliance that other parts of the compartment,and thus accommodate the volumetric excursions of the compartmentwithout causing substantial pressure changes. The compliant reservoirsmay be as simple as flexible caps over holes in the housing.Alternatively, open capillary channels may be connected to thecompartment. Further still, compressive gas pockets may be disposed inthe compartment. One or more of such techniques may be used inconjunction with each other to further reduce residual fluid pressure.

Control of Residual Fluid Pressure by Configuring the Second SupportRadius

In a preferred embodiment, a residual fluid pressure may be reduced orsubstantially eliminated by properly selecting the second supportradius. By configuring the second support (or “inner support”) radius(second support radius) to be approximately a factor of 1/√2 (or 0.707)times the first support (or “edge support”) radius (edge support radius)may, over a wide range of loads and configurations, serve tosubstantially eliminate residual fluid pressure. In other embodiments,control over residual fluid pressure may be desirable. In such cases,the second support radius may be configured to be slightly smaller orlarger than the 1/√2 factor times the first support radius. For example,if the volume imbalance is allowed to range from zero to about half thevolume under dome of the deflected clear aperture of the opticalsurface, the ratio of second support radius divided by the edge supportradius may vary from about 0.66 to about 0.76.

Control of Residual Fluid Pressure by a Compliant Bladder

In another embodiment, a residual fluid pressure may be reduced orsubstantially eliminated in the compartment by providing a bladdermember (bladder) in communication with a portion of the compartment. Thebladder may preferably have greater compliance than the opticalsurfaces, first or second support, or any other member of thecompartment. In one configuration, the bladder may be configured withsubstantially greater compliance than any other member of the device.The bladder may comprise a diaphragm, flexible or stretchable film, forexample, elastomeric film, PDMS, polyester, or any other flexible orcompliant material. The bladder may be disposed in communication with aportion of the compartment such that a first surface of the bladder(first bladder surface) may be in communication with the fluid internalto the compartment. Likewise, a second surface of the bladder (secondbladder surface) may be in communication with the environment or mediadisposed external to the compartment. In this fashion, in response to apositive residual fluid pressure, the bladder may deflect outward fromthe compartment. Similarly, in response to a negative residual fluidpressure, the bladder may deflect inward to the compartment. Further, inconfigurations where a diaphragm-like bladder is fastened to an outerwall of a compartment, a negative residual fluid pressure may draw thebladder inward in a concave fashion, thereby helping to preventdelamination of the bladder from the surface to which it is mounted.Since the bladder may have greater compliance than the optical surfaces,the residual pressure may result in substantially only causing adeflection in the bladder and not the optical surfaces. Similarly, sincethe bladder may have greater compliance than the first and secondsupports, the residual pressure may result in substantially only causinga deflection in the bladder and not first and/or second support.

Control of Residual Fluid Pressure by a Compliant Reservoir

In another embodiment, a residual fluid pressure may be reduced orsubstantially eliminated in the compartment by providing a reservoirmember (reservoir) in communication with a portion of the compartment.In one embodiment the reservoir may be compliant and function similarlyto a bladder as described in the previous embodiment. The reservoir mayinclude a compliant bellows member and be configured for fluid flowbetween the compartment and bellows member. In one configuration, thereservoir may be substantially ring-shaped and include a compliantbellows in communication with its sidewall. A first surface of thereservoir may be disposed in communication with the first opticalsurface, and a second surface of the reservoir may be disposed incommunication with the second optical surface. In one configuration thefirst and second surfaces of the reservoir may be fastened to, and forma seal with, the first and second optical surfaces. The radius of thereservoir (reservoir radius) may be greater than the clear apertureradius and/or second support radius. By way of example, in the presenceof positive residual fluid pressure in the compartment, fluid may flowfrom the compartment into the reservoir (or bladder member of thereservoir), resulting in a portion of the reservoir expanding. Likewise,in presence of negative residual fluid pressure in the compartment,fluid may flow from the bladder member of the reservoir intocompartment, resulting in the bladder member of the reservoircontracting. In alternate configurations, one or more of the reservoir,bladder or bladder member of the reservoir may be configured as a memberof, integrated with, or in communication with the first support, secondsupport, or any other desirable member of the compartment and/or device.

Control of Residual Fluid Pressure by a Compliant Bladder with AnnularElements

In another embodiment, one or more of first support and/or secondsupport may include one or more channel members (or “channels”). Thechannels may serve to provide a reservoir or route for fluid to moveinto or out of the compartment in accordance with changes in residualfluid pressure. The channels may include channel wall regions and mayinclude any desirable surface treatment. Further, the channels mayinclude bellows structures such as annular-shaped members connected byelastomeric ring-shaped seals. The annular-shaped members may have asubstantially bending-modulus and may include materials such as thinglass (for example, glass having 10-500 micron thickness), plastic orany generally stiff material. While the annular-shaped members mayinclude stiff material, they may preferably have greater compliance thanthe optical surfaces, supports, and/or any other part of the device thatundergoes deflection. The seals may contribute to the compliance,however, a significant portion of the compliance may be provided by theannular-shaped elements. Although other materials may be desirable forconstructing the bellows, the use of glass is beneficial for reducingplastic deformation effects associated with metals, polymers and othermaterials.

Control of Residual Fluid Pressure by a Reservoir Having CompliantlySealed Channels

In one embodiment, the compartment may include a reservoir member havingchannels (reservoir channels) configured for fluid flow. The reservoirmay be ring shaped and may be in communication with a portion of thefirst support, second support or any other member of the compartment. Inresponse to a residual fluid pressure, fluid may flow between thecompartment and one or more of the reservoir channels, thereby reducingor eliminating the residual fluid pressure. The external ends of thereservoir channels may be sealed with compliant (such as elastomeric)seals in order to prevent the fluid from escaping the channels. In thisfashion, the compliant seals may additionally deflect, similar to thebellows described above, in order to assist in the elimination orreduction of residual fluid pressure.

Control of Residual Fluid Pressure by a Reservoir Having Open CapillaryChannels

In another embodiment, the reservoir channels may be sufficiently smallin diameter such that capillary forces may be employed to prevent thefluid from escaping from the compartment. In this fashion, fluiddisposed inside a capillary channel may form a meniscus. Capillaryforces may then dominate gravity or other forces and prevent the fluidfrom exiting the reservoir channels and escaping the reservoir and/orcompartment. As a result of the capillary forces retaining the fluid inthe channels, the ends of the channels may be left unsealed or “open”.Additionally, a small amount of oil may be disposed in the proximity ofthe ends of the reservoir channels. For example, oil that is immisciblewith the fluid may follow the motion of fluid as it is driven by theresidual fluid pressure in the compartment. Further, the oil may beinert and have low vapor pressure in order to suppress the evaporationof it and the fluid, thereby prolonging the operating life of the deviceor its mean time between refills.

Control of Residual Fluid Pressure by a Reservoir Having OpenElectrowetting Channels

In an alternate embodiment, the reduction or elimination of the residualfluid pressure may be controlled by actively modulating the capillaryforces of the fluid in the reservoir channels. Such active modulation ofthe capillary forces may be achieved by employing electrowetting. Thefluid may be provided with a small degree of electrical conductivity,for instance by adding an ionic salt. An electrode may be disposed toconnect the liquid to a controlled electrical potential. A thinhydrophobic insulator may be provided to separate the fluid from acounter electrode disposed in the reservoir, thereby forming acapacitor. As the capacitor is charged, the wetting (or contact angle)may change in order to minimize the overall system energy, which mayinclude electrostatic and capillary contributions. The change of contactangle may be accompanied by movement of the meniscus of the fluid,whereby the movement of the meniscus may result in the advancing orreceding of the fluid in the capillary reservoir channels. In thisfashion, the controlled movement of the fluid in the reservoir channelsserves to modify the residual fluid pressure or other pressureconditions in the compartment. The ability to control position of themeniscus, and hence the fluid pressure, may provide a beneficial addeddegree of control (i.e., in addition to a concentrated or other load)over the optical properties of the adaptive fluidic device. As describedabove, oil may be disposed in the capillary channels in order to preventevaporation of the fluid. Alternatively, the roles of the oil andconductive fluid may be reversed, if the optical properties of the oilare preferable over the fluid. In such case, the polarity of the controlvoltage may be reversed and provisions may be made for a capillarychannel with characteristics that may include the following: anelectrode may be brought into direct contact with the conductive fluideither in the capillary channel or in an auxiliary external reservoir;and/or a second electrode may be localized under a hydrophobic insulatoronly in the region of the capillary channel where the interface betweenthe oil and the conductive fluid is likely to be positioned.

Gas Bubble Reservoir for the Control of Residual Fluid Pressure

In an alternative embodiment, residual fluid pressure may be reduced bydisposing (or trapping) a sufficiently large air bubble (or gas pocket,or region of other compressive medium) in a portion of the compartment.The gas pocket may function similarly to a compliant reservoir andaccommodate volume excursions with minimal pressure changes. The size ofthe required gas pocket may be estimated from the ideal gas law, whichprovides that the product of pressure and volume of the gas pocket mustremain constant. Therefore, the fractional change in volume of the gasvolume must be equal and opposite in sign to the fractional change inpressure on gas pocket. For example, if, at atmospheric pressure, thegas pocket occupies a volume 100 times larger than the net volumeexcursion, then the pressure excursion in the gas pocket will be only1/100, or 1%, of the atmospheric pressure. To create and stabilize a gaspocket in compartment, the gas pocket may be disposed in an outersub-compartment or other region of the compartment. Portions of theinner support and/or the walls of the compartment may be surfaceengineered. In surface engineering, materials are treated in such a wayas to modify their wettability by the fluids of interest. For example,the selective and judicious deposition of hydrophobic and/or hydrophiliccoatings and capillarity effects may help attract and localize a bubbleor gas pocket in a desirable part of the compartment or device. Forexample, hydrophilic coating of an inner sub-compartment (such asregions inside the clear aperture) and hydrophobic coating of an outersub-compartment (such as regions outside the clear aperture), may assistin preferentially locating and retaining such bubbles in the outersub-compartment. In this fashion, bubbles may be kept out of the clearaperture and thus may be prevented from having deleterious effects onoptical properties of the device.

Independent Control of Pressure and Bending

In still other embodiments, it may be advantageous for spherical andaspheric deflection of a stiff optical surface to be controlledindependently of each other. In one embodiment, a first actuator (forexample, a ring bender) and concentric supports may provide aring-on-ring concentric load to a stiff optical surface. Such concentricloading may result in the clear aperture of optical surface deflectingwith spherical curvature. Likewise, a pressure-control actuator (forexample, a pump) may be configured to communicate a fluid pressure tothe compartment, resulting in an aspheric deflection of the opticalsurface, and, particularly, the clear aperture of the optical surface.Independent control over multiple forms of applied loads (e.g., theconcentrated and distributed) may enable control over multiple aspectsof the optical surface profile and optical properties of the device. Forexample, in the case of an adaptive fluidic lens, the radius ofcurvature of a stiff optical surface may be controlled by bending undera ring-on-ring load, generally corresponding to control of the ZernikeZ4 defocus term. Further, asphericity (for example, the conic constant)of the optical surface may be controlled by fluid pressure, generallycorresponding to control of primary spherical (Z8), secondary spherical(Z15), or higher order spherical Zernike terms.

Fluidic Adaptive Wavefront Corrector Wavefront Corrector—Introduction

In previous embodiments, adaptive fluidic devices are described whereinboth the curvature and height of the vertex of a deflected opticalsurface may be controlled by an applied load. As described above, suchcontrol of the optical surface may enable control of optical propertiesof the device such as defocus and spherical aberration Zernike terms.Alternatively, it may be desirable for an adaptive optical device to beoptimized for control of only spherical aberration terms, whilegenerally leaving focus unchanged. Such control may be enabled byconstraining the vertex while permitting other portions of the opticalsurface to undergo deflection, and may be useful in adaptive wavefrontcorrection applications. For example, as atmospheric turbulence maycause fluctuations in the Strehl ratio of a telescope, an adaptivefluidic Schmidt corrector plate may be useful for dynamically correctingspherical aberrations without substantially changing the telescope'sfocus.

Adaptive Fluidic Wavefront Corrector Actuated by Fluid Pressure

In one such embodiment, an adaptive fluidic corrector plate may includea lens compartment bounded by two circular disk-shaped optical surfaces(first and second optical surfaces), and a ring-shaped edge support(edge support) disposed between the optical surfaces near their edges.The edge support may have an edge support radius similar to the radiusof the edge of first and/or second optical surfaces. A fluid may bedisposed in the compartment. A pump actuator may be disposed incommunication with, and provide a controllable fluid pressure to, thecompartment. In this fashion, pump provides an applied distributed loadto the compartment. First optical surface and/or second optical surfacemay be configured for deflection in response to an applied load. A firstaxial support may be disposed external to the compartment and incommunication with first optical surface in the proximity of the opticalaxis. For example, the first axial support may include a rigid convexsurface (such as a rigid glass lens), wherein the convex vertex of thefirst axial support may be disposed in communication with the vertex offirst optical surface. In this fashion, first axial support may besimilar to a simple pin support. Further, first axial support may beconfigured to be substantially optically transparent at a desired rangeof wavelengths. An index-matching second fluid may optionally bedisposed externally to compartment and in communication with an externalside of first optical surface and a side of first axial support. In thisfashion, the pump may provide an applied load in the form of a change influid pressure to the compartment. In response to the applied load,first optical surface may deflect. In response to the applied load anddeflection of first optical surface, first axial support may provide areaction force to the vertex of first optical surface. In this fashion,first optical surface may be constrained from deflection at regions nearits edge by edge support, as well as near the optical axis by firstaxial support. Since the vertex of first optical surface may beconstrained (i.e., the height of the vertex may not change) by axialsupport, while other radial regions may be allowed to deflect, firstoptical surface may exhibit deflected shape profiles similar to Zernikepolynomial terms for spherical aberration. Optionally, both secondoptical surface and first optical surface may be configured fordeflection. In such case, a second axial support, and second fluid, mayoptionally be disposed in communication with second optical surface in afashion similar to first axial support. As may be desirable foroperation in transmission mode (i.e., wherein light may be transmittedthrough at least a portion of the clear aperture of the device), any ofthe components of the device may be configured to exhibit high opticaltransmission at a desired range of wavelengths. Further, additionalsupports and index-matching fluids may be provided to control vertexdeflection and reduce unwanted reflections and/or interference effectsthat could hinder its performance. Yet further, in alternativeembodiments, one or more of first and/or second optical surfaces, firstand/or second axial supports, fluids, index-matching fluids, and/or anyother part of the device may be configured to be at least partiallyreflecting at a desired range of wavelengths. In this fashion, thedevice may function in reflection mode, rather than in a transmissivemode of operation.

Adaptive Fluidic Wavefront Corrector Actuated by Pin-on-Ring Load

In another alternative embodiment, the first and/or second axial supportmay be configured to be displaced with respect to the position of edgesupport. Pump actuator may be replaced with a force actuator configuredto provide an axially-directed (i.e., along the optical axis) load tofirst and/or second supports, resulting in a displacement of firstand/or second axial support with respect to edge support. Alternatively,actuator may be configured to displace edge support relative to firstand/or second axial support. In this fashion, the actuator, edgesupport, first and/or second axial supports may be configured to apply aconcentrated pin-on-ring load to first and/or second optical surfaces.In the present embodiment, the vertex may be simultaneously subjected toan applied concentrated load, and constrained from other change inheight, by first and/or second axial support. The compartment mayinclude optional reservoir and/or bellows for the control of residualfluid pressure.

Adaptive Fluidic Wavefront Corrector Actuated by Ring-on-Ring Load

In an alternative embodiment, a ring-shaped second support may bedisposed with a radius smaller than the edge support radius. An actuatormay be configured with first and/or second supports to apply aconcentrated ring-on-ring load to first and/or second optical surfaces.The applied load may result in the bending deflection of one or more offirst and/or second optical surfaces.

Fluidic Adaptive Wavefront Corrector—Internal Axial Support

In above embodiments, the applied load may be configured so that firstoptical surface deflects in a convex fashion, wherein the vertex maydeflect along the optical axis, outward, or away from, the center of thecompartment. Alternatively, the applied load may be configured so thatfirst optical surface deflects in a concave fashion, wherein the vertexmay deflect along the optical axis, inward, or toward the center of thecompartment. For example, the applied load may include a negative fluidpressure. Alternatively, ring-shaped supports may be configured to bendfirst optical surface in a concave fashion. In such concave cases, thefirst axial support may be disposed internal to compartment, providing apin-support reaction force and constraining deflection of the vertex ofthe first optical surface in a fashion similar to theexternally-disposed configuration described above.

Operation of a Fluidic Wavefront Corrector

The above described embodiments may operate as follows. Light may betransmitted through first axial support, second index-matching fluid,enter compartment through first optical surface, exit compartmentthrough second optical surface, and be transmitted through additionalindex-matching fluid and second axial support. In response to theapplied load, first optical surface may deflect. Further, as deflectionincreases, the stress between the between the first axial support infirst optical surface, may also increase. As the fluidic optical deviceis actuated, the first axial support restrains the position of thevertex of the first optical surface from moving outward along theoptical axis or, prevents the vertex of first optical surface frombulging outward). As a result of the restraint (or support) at thevertex, the peripheral regions of the first optical surface (i.e.,regions disposed between the center and the edge) may bulge instead.Such control of first optical surface may result in deflections similarto Zernike spherical aberration polynomials, and hence control ofspherical aberration properties of the device. Further, by controllingthe height of the vertex of the first optical surface (which may beachieved, for example, by use of an actuator to control the axialposition of first axial support), the first optical surface may exhibitdeflection similar to the defocus Zernike polynomial, thereby allowingcontrol over the focus of the device.

DETAILED FIGURE DESCRIPTIONS

FIG. 1 is a three-dimensional cross-sectional view of a portion of acompartment 1000 of an adaptive fluidic optical device 2000, showingdeflected optical surface 2002 and edge support 2004 in the presence ofan applied load. Edge support 2004 may be at least partially rigid andsimilar to a fixed support. Optical surface 2002 may generally besimilar to a thin (or Kirchhoff) plate and disposed in communicationwith edge support 2004. In response to applied load, optical surface2002 may exhibit an inflection (indicated by 2006) at a radial regionand a vertex (indicated by 2010). However, when under no applied load,optical surface 2002 may exhibit substantially planar geometry,resulting in the reduction or elimination of inflection 2006 and vertex2010. In another embodiment, inflection 2006 may be at least partially aresult of the undeflected shape of optical surface 2002. For example,optical surface 2002 may be formed by molding or grinding and polishingand exhibit an inflection in some or all states of applied load.Alternatively, optical surface 2002 may be configured to exhibit aninflection point under no applied load, but under applied loadinflection may disappear. Compartment 1000 may be filled with a fluid(not shown).

FIG. 2 is a three-dimensional cross-sectional view of a portion of acompartment of an adaptive fluidic optical device 2000, showing thedeflection of optical surface 2002 in communication with an edge support2004. Edge support 2004 may be compliant and similar to a hinge support.Edge support 2004 may be configured with compliance such that deflectionof optical surface 2002 results in a pivoting (or angular displacement)3002 of outer edge 3004 of optical surface 2002. Pivoting 3002 of outeredge 3004 may lead to a reduced bending moment in optical surface 2002(compared to the embodiment depicted in FIG. 1), and resultingelimination of an inflection. When edge support 2004 is sufficientlycompliant, optical surface 2002 may pivot freely in response to anapplied load, and exhibit substantially spherical curvature in a clearaperture region 2007.

FIG. 3 is alternative embodiment of the configuration depicted in FIG.2, showing a cross-sectional schematic representation of a deflectedoptical surface 2002 with an outer edge 3004 supported by a partiallycompliant edge support 2004. Due to lack of perfect compliance in edgesupport 2004, edge 3004 is limited in its ability to pivot in responseto an applied load. As a result of such limited pivoting, inflection2006 is still present but it is shifted to a greater radial distancefrom vertex 2010, as compared to the rigid-support configurationdepicted in FIG. 1. Such shifting of inflection 2006 to greater radiallocations may improve aspheric curvature in a clear aperture region 2007of deflected optical surface 2002.

FIG. 4 is a cross-sectional schematic representation of the embodimentdepicted in FIG. 1 wherein optical surface 2002 is clamped by fixed edgesupport 6002. Applied load may be disposed in the form of a distributedload (or fluid pressure, indicated by arrows 6004). Distributed load6004 is shown applied internally to compartment 1000 and uniformlyacross optical surface 2002. However, distributed load 6004 mayalternatively be applied to any portion of compartment and/or opticalsurface 2002, as well as non-uniformly over any portion of compartmentand/or optical surface 2002. Further, distributed load 6004 is shown asa positive pressure, causing vertex 2010 to deflect outward from centerof compartment 1000. Alternatively, distributed load 6004 may be appliedexternally to compartment 1000, and may result in vertex 2010 deflectinginward toward center of compartment 1000. Generally, distributed load6004 may be positive and/or negative and may be disposed internallyand/or externally to compartment 1000, resulting in a pressuredifferential between the top and bottom sides of optical surface 2002(or between internal and external regions of compartment 1000).

FIG. 5 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 4. However, in FIG. 5, optical surface 2002is now supported by simple edge support 2004 instead of fixed edgesupport 6002 (see FIG. 4). Edge support 2004 may be compliant anddisposed internally and/or externally to compartment 1000.

FIG. 6 is a cross-sectional schematic representation of a deflectedoptical surface 2002 in a configuration that includes fixed edge support6002 and inner ring support 9002. Fixed edge support 6002 may be mountedto a portion of a compartment 1000 and/or housing (not shown). Innerring support 9002 may be similar to a simple support or fulcrum.Further, inner ring support 9002 may be disposed in communication withoptical surface 2002 at a radius smaller than the radius of fixed edgesupport 6002. An actuator (not shown) may provide the applied load,which may be in the form of a “ring-on-ring load”, indicated by arrows9004). In communicating applied load 9004 to optical surface 2002, innerring support 9002 may be displaced relative to the position of fixededge support 6002 in a direction substantially parallel to optical axis9010. Alternatively, the functions of supports 6002, 9002 may bereversed, wherein fixed edge support 6002 may be displaced relative toposition of simple inner ring support 9002. For example, fixed edgesupport 6002 may be configured for displacement, while simple inner ringsupport 9002 may be mounted to a portion of a compartment and/or housing(not shown). Generally, either or both supports 6002, 9002 may bedisplaced relative to the position of the other in order to deliver anapplied load to optical surface 2002.

FIG. 7 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 6 However, in FIG. 7, fixed edge support 6002(see FIG. 6) is replaced with a simple edge support 2004.

FIG. 8 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 6. However, in FIG. 8, control of thedisplacement of vertex 2010 is enabled by replacing simple inner support9002 (see FIG. 6) with an axial support 12002. Axial support 12002 maybe similar to a simple or pin support and may have substantially highoptical transmission at a desired range of wavelengths. Actuator (notshown) may provide the applied load, which may be in the form of a“pin-on-ring load”, indicated by arrows 9020). In communicating appliedload 9020 to optical surface 2002, axial support 12002 may be displacedrelative to the position of fixed edge support 6002 in a fashion similarto that depicted in FIG. 6. Alternatively, the functions of supports6002, 12002 may be reversed, wherein fixed edge support 6002 may bedisplaced relative to position of axial support 12002.

FIG. 9 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 8. However, in FIG. 9, fixed edge support6002 has been replaced with a simple edge support 2004.

FIG. 10 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 8. However, in FIG. 10, simple inner ringsupport 12002 has been added. Ring-on-ring load 9004 may be actuatedindependently from pin-on-ring load 9020. As a result of independentapplied loads 9004, 9020, the asphericity as well as radius-of-curvatureof optical surface 2002 may be controlled.

FIG. 11 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 6. However, in FIG. 11, distributed load 6004has been added as an applied load, independent from ring-on-ring load9004. In FIG. 11, optical surface 2002 is shown deflecting in a convexfashion toward inner ring support 9002, however, applied loads 9004,6004 may be configured in any fashion such that optical surface 2002 maydeflect in generally either a convex or concave direction. In general,any applied load may be configured in any desired fashion in order tocause optical surface 2002 to deflect in any desired fashion. Forexample, distributed load 6004 is shown in FIG. 11 configured to opposeload 9004 applied to simple inner support 9002. Alternatively,displacement load 9004 and distributed load 6004 may be applied in thesame direction. Distributed load 6004 may be provided by a positive ornegative fluid pressure applied to the top, bottom, or both sides ofoptical surface 2002. As a result of independent applied loads 6004,9004, the asphericity as well as radius-of-curvature of optical surface2002 may be controlled.

FIG. 12 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 11. However, in FIG. 12, distributed load6004 is applied non-uniformly to optical surface 2002 with greatestpressure disposed in the clear aperture region 2007.

FIG. 13 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 11. However, in FIG. 13, simple edge support2004 now replaces fixed edge support 6002 (see FIG. 11).

FIG. 14 is a schematic cross-sectional representation similar to thestructure depicted in FIG. 10. However, in FIG. 14, distributed load6004 is added to pin-on-ring load 9020 and ring-on-ring load 9004.

FIG. 15 is a three-dimensional cross-sectional view of fluidic lenselement 27000 that includes fluid-filled compartment 1000 bounded byfirst optical surface 2002 and second optical surface 2012. Compartment1000 may additionally be bounded by a first compliant edge support(first edge support, or edge support) 2004. Further, first edge support2004 may form a seal with optical surfaces 2002, 2012, and compartment1000 may be filled with fluid 100. A portion of the top surface of firstoptical surface 2002 may be disposed in communication with a second edgesupport (second edge support or external edge support) 27010. Similarly,a portion of the bottom surface of second optical surface 2012 may bedisposed in communication with a third edge support (third edge supportor external support) 27012. Supports 2004, 27010, 27012 may beconfigured with support radii approximately equal to the edge radii ofoptical surfaces 2002, 2012. External support 27010 may be disposed incommunication with first actuator 27014. Likewise, external support27012 may be disposed in communication with second actuator 27016.Actuator assemblies 27014, 27016 may be in disposed in communicationwith housing 27018 and may provide an applied axial load that may drivesupports 2004, 27010, 27012 in a state of compression. A portion ofhousing, adjustable housing member 28004, may be adjustable (forexample, along the optical axis) in order to dispose a desired amount ofpreload to one or more of actuators 27014, 27016, supports 2004, 27010,27012, optical surfaces 2002, 2012 or any other part of the compartment1000 or device 27000. The position of adjustable housing member 28004may be set by any desirable technique, for example, by threading matingsidewalls of adjustable housing member 28004 and housing 27018. As firstedge support 2004 compresses and relaxes in response to changes in theapplied load, fluid pressure within compartment 1000 may likewiseincrease and decrease, thereby resulting in deflection of opticalsurfaces 2002, 2012.

FIG. 16 is a three-dimensional cross-sectional view of fluidic lenselement 28000 similar to the structure depicted in FIG. 15. However, inFIG. 16 simple inner support 28002 is added to the assembly. Simpleinner support 28002 may be disposed internal to compartment 1000 and incommunication optical surfaces 2002, 2012. Simple inner support 28002may form a seal with optical surfaces 2002, 2012 and separatecompartment 1000 into two distinct sub-compartment regions; an innersub-compartment 28006 and an outer sub-compartment 28008. Simple innersupport 28002 may be configured to prevent fluid communication betweensub-compartments 28006, 28008. Actuators 27014, 27016 may deliver anaxial compressive load to edge supports 2004, 27010, 27012, and appliedload to edge of optical surfaces 2002, 2012. Such loading may result inthe axial compression of first edge support 2004 relative to simpleinner support 28002, further resulting in a concentrated concentricring-on-ring loading and deflection of optical surfaces 2002, 2012. Dueto the lack of fluid communication between sub-compartments 28006,28008, deflection of optical surface 2002, 2012 may result in a residualfluid pressure. Such residual fluid pressure may serve to provideadditional asphericity into the curvature of deflected optical surfaces2002, 2012.

FIG. 17 is a three-dimensional exploded cross-sectional view of fluidiclens element 28000 depicted in FIG. 16.

FIG. 18 is a three-dimensional exploded cross-sectional view of fluidiclens element 31000 similar to the structure depicted in FIG. 16. Howeverin FIG. 18, perforated simple inner support (perforated support) 30002replaces simple inner support 28002 (see FIG. 16). Fluid pass-throughs30004 are disposed in sidewall of perforated support 30002 and permitfluid communication between sub-compartments 28006, 28008 (see FIG. 16).Such fluid communication enables the control of fluid pressure betweensub-compartments 28006, 28008. In this fashion, compartment 1000 may beconfigured such that residual fluid pressure may be substantiallynegative, positive or zero pressure.

FIG. 19 is a cross-sectional view of fluidic lens element 31000 similarto the device depicted in FIG. 18, illustrating one example of actuationof the device. In FIG. 19, actuators 27014, 27016 are shown in a firststate of actuation. First state of actuation results in substantiallyzero applied load being delivered to compartment 1000; consequently,optical surfaces 2002, 2012 are shown in an undeflected state.

FIG. 20 is a cross-sectional view of fluidic lens element 31000 similarto the device depicted in FIG. 19, however, actuators 27014, 27016 arenow shown in a second state of actuation. Second state of actuationresults in an applied load being delivered to compartment 1000;consequently, optical surfaces 2002, 2012 are shown to be in a state ofdeflection. Applied load includes a ring-on-ring load delivered bysupports 30002, 27010, 27012, resulting in a deflection of opticalsurfaces 2002, 2012. Deflection of optical surfaces 2002, 2012 mayresult changes in fluid pressure between sub-compartments 28006, 28008.Fluid 100 may flow through fluid pass-throughs 30004 in order to reduceor eliminate residual fluid pressure (i.e., the relative pressurebetween sub-compartments 28006, 28008).

FIG. 21 is a cross-sectional view of fluidic lens element 21000 similarto the structure depicted in FIG. 19. The applied load may be providedby a pressure control actuator 21100. Pressure control actuator 21100(for example, a pump) may be disposed in communication with, and controlfluid pressure in, compartment 1000.

FIG. 22 is a three-dimensional exploded cross-sectional view of fluidiclens element 30000 similar to the structure depicted in FIG. 18. Howeverin FIG. 22, second optical surface 2012 may have any desired deflectionor mechanical properties, for example, it may be similar to a thick orrigid plate (see FIG. 18). By way of further example, the second opticalsurface 2012 may exhibit substantially less deflection than the firstoptical surface 2002 or substantially no deflection at all. Further,actuator 27014, may be configured to deliver applied load to the edge offirst optical surface 2002.

FIG. 23 is a three-dimensional view of a perforated support 30002.Perforated support 30002 may include support rim 30020 for communicatingapplied load with optical surfaces 2002, 2012 and fluid pass-throughs30004 for providing fluid communication between sub-compartments.Support rim 30020 may be perforated or segmented in order to providefluid communication between regions of compartment 1000 disposed oneither side of it. Alternatively, support rim 30020 may be configured ascontinuous rim if such fluid communication is not required or isprovided by other parts of perforated support 30002 and/or another partof the compartment 1000 and/or device. Perforated support 30002 furthermay include spider-leg 32002 and outer-rim 32010 protrusions to assistin centering of the support within lens element 30000. Spider-leg 32002and outer-rim 32010 may additionally provide axial compliance toperforated support 30002, permitting support rim 30020 to be easilydisplaced in a direction parallel to optical axis 9010. Support rim30020 and/or any other part of perforated support 30002 may define orbound the clear aperture 2007.

FIG. 24 is a three-dimensional cross-sectional view of fluidic lenselement 33000 similar to the structure depicted in FIG. 18. However inFIG. 24, simple inner support with bellows (bellows support) 33002 mayreplace both perforated support 30002 and edge support 2004 (see FIG.18). Bellows support 33002 may include support rim 33020, fluidpass-throughs 30004, and compliant bellows member 33050. In response toresidual fluid pressure, fluid may flow between inner sub-compartment28006 and bellows member 33050 via fluid pass-throughs 30004. In thisfashion, bellows member 33040 may inflate and deflate so as to reduce oreliminate residual fluid pressure.

FIG. 25 is a three-dimensional exploded cross-sectional view of fluidiclens element 33000 similar to the structure depicted in FIG. 24.

FIG. 26 is a three-dimensional cross-sectional view of adaptive fluidiclens element 33000, similar to the device depicted in FIG. 24. In FIG.26, actuators 27014, 27016 are shown in a first state of actuation.First state of actuation results in substantially zero applied loadbeing delivered to compartment 1000; consequently, optical surfaces2002, 2012 are shown in an undeflected state.

FIG. 27 is a three-dimensional cross-sectional view of adaptive fluidiclens element 33000, similar to the device depicted in FIG. 26. However,in FIG. 27, actuators 27014, 27016 are now shown in a second state ofactuation. Second state of actuation results in an applied load beingdelivered to compartment 1000; consequently, optical surfaces 2002, 2012are shown in a state of deflection. Applied load includes a ring-on-ringload delivered by supports 33002, 27010, 27012, and may also include afluid pressure load if residual fluid pressure, resulting fromdeflection of optical surfaces 2002, 2012, is non-zero.

FIG. 28 is a three-dimensional cross-sectional view of fluidic lenselement 57000 similar to the structure depicted in FIG. 26. However inFIG. 28, bending-modulus bellows support (bending bellows support) 27500may replace bellows support 33002 (see FIG. 26). Bending bellows support27500 may include annular-shaped members 27510, 27512 connected byelastomeric ring-shaped seals 27520, 27522, 27524. In operation,annular-shaped members 27510, 27512 may deflect in a fashion thatreduces or eliminates residual fluid pressure in compartment 1000, whichmay result from actuation.

FIG. 29 is a three-dimensional cut-away view of fluidic lens element35000 similar to the structure depicted in FIG. 24. However in FIG. 29,support with fluid capillary channels (capillary support) 35002 replacesbellows support 33002 (see FIG. 24). Capillary support 35002 includessupport rim 33020, fluid pass-throughs 30004 and fluid channels 35010(note, in various embodiments of the present invention, fluidpass-throughs 30004 may be similar to fluid channels 35010). In afashion similar to bellows member 33040 (see FIG. 24), fluid may flowinto and out of fluid channels so as to reduce or eliminate residualfluid pressure. Fluid channels 35010 may employ capillary forces,hydrophobic or other coatings, electrowetting, oils and/or other fluidsin order to further control properties of the fluid. Further, fluidchannels 35010 may be open-ended (indicated by openings 35020) oroptionally sealed with compliant bellows or diaphragms (not shown) tohelp contain fluid.

FIG. 30 is a three-dimensional exploded view of fluidic lens element35000 (see FIG. 29).

FIG. 31 is a schematic cross-sectional view of an electrowettingcapillary support 35002 similar to the structure depicted in FIG. 29.Preferably, in the present embodiment, residual fluid pressure issufficiently low that it may be controlled by electrowetting. Capillarysupport 35002 includes openings 35020 and is disposed in fluidcommunication with compartment 1000. Fluid 100 forms a meniscus 29080and is prevented from following gravity by capillary forces in fluidchannel 35010. Fluid 100 is electrically conductive and connected to acontrolled electrical potential 29100. Thin hydrophobic insulator 29110separates the fluid 100 from counter electrode 29120, thereby forming acapacitor. Counter-electrode 29120 may be an electrically conductivestructural material (for example, aluminum or stainless steel) andintegral to capillary support 35002. As the capacitor is charged, thewetting angle changes and is accompanied by movement of the meniscus29080, thus effectively advancing or receding fluid 100 in fluid channel35010 and modifying residual fluid pressure in compartment 1000.Immiscible oil (oil) 35100 may be added to fluid disposed in fluidchannel 35010. Oil 35100 would simply follow theelectrowetting-controlled motion of fluid 100.

FIG. 32 is a cross-sectional view of fluidic lens element 43000 withcompartment 1000 including fluid (not shown) optical surfaces 2002, 2012and reservoir bladder 43002. Reservoir bladder 43002 forms a seal withoptical surfaces 2002, 2012. Actuators 27014, 27016 may be mounted attheir outer edges by housing 27018 and adjustable housing member 28004.Reservoir bladder 43002 is substantially more compliant than opticalsurfaces 2002, 2012, wherein it if configured for easily axialcompression. External ring supports 43006, 43008 may be disposed incommunication with actuators 27014, 27016 and optical surfaces 2002,2012. External ring supports 43006, 43008 are configured to functionsimilarly to simple supports. In response to an axial motive forceprovided by actuators 27014, 27016, external ring supports 43006, 43008may communication an axial applied load to optical surfaces 2002, 2012,respectively. External ring supports 43006, 43008 may be fastened, oraffixed, to optical surfaces 2002, 2012 with a compliant adhesive orelastomer (indicated by meniscuses 43016, 43018). In FIG. 32, actuators27014, 27016 are shown in a first state of actuation. First state ofactuation results in substantially zero applied load being delivered tocompartment 1000; consequently, optical surfaces 2002, 2012 are shown inan undeflected state. In response to first state of actuation, reservoirbladder 43002 is shown inflated to a first shape to accommodate a firstvolume of displaced fluid 43020.

FIG. 33 is a cross-sectional view of fluidic lens element 43000 in asecond state of actuation. Actuators 27014, 27016 provide an axialmotive force, resulting in a ring-on-ring applied load being deliveredto optical surfaces 2002, 2012 through supports 43006, 43008, 2004. Inresponse to second state of actuation and resulting applied load,optical surfaces 2002, 2012 are shown in a deflected state. Further, inresponse to second state of actuation and resulting residual fluidpressure, reservoir bladder 43002 is shown inflated to a second shape toaccommodate a second volume of displaced fluid 43020. In this fashion,as applied load is adjusted, the resulting changes in residual fluidpressure may cause fluid to flow between sub-compartment 28006 andreservoir bladder 43002. Likewise, reservoir bladder 43002 will expandand contract in response to the flow of fluid into and out of it.

FIG. 34 is a cross-sectional view of an adaptive fluidic lens 41000similar to the embodiment depicted in FIG. 19. However, in FIG. 19 oneor more gas pocket reservoir (gas pocket) 31102 is disposed incompartment 1000. Preferably, gas pocket 31102 is disposed insub-compartment 28008. Surfaces internal to inner sub-compartment 28006may be treated with a hydrophobic coating to help prevent gas pocketfrom entering inner sub-compartment 28006. Likewise, surfaces internalto outer sub-compartment 28008 may be treated with a hydrophilic coatingto help retain gas pocket in outer sub-compartment 28008. Further, fluidpass-throughs 30004 may be configured in such a fashion that capillaryaction substantially prevents gas pocket 31102 from transiting throughfluid pass-through 30004 and entering inner sub-compartment 28006. Bypreventing gas pockets 31102 from entering inner sub-compartment 28006,gas pocket 31102 is likewise prevented from obscuring clear aperture andcausing undesired optical effects in the device. In FIG. 34, adaptivefluidic lens 41000 is shown in a first state of actuation whereinoptical surfaces 2002, 2012 are undeflected and gas pocket 31102 is in afirst state of volume and pressure.

In FIG. 35, adaptive fluidic lens 41000 is shown in a second state ofactuation wherein optical surfaces 2002, 2012 are deflected and gaspocket 31102 is in a second state of volume and pressure. As a result ofdeflection of optical surfaces 2002, 2012, a residual fluid pressure mayoccur in compartment 1000. In the example of FIG. 35, residual fluidpressure may be negative, thereby subjecting gas pocket 31102 to a dropin pressure. Following the ideal gas law, such drop in pressure mayresult in gas pocket 31102 undergoing an increase in volume.

FIG. 36 is a three-dimensional cross-sectional view of fluidic lenselement 45000 similar to the structure depicted in FIG. 9. Axial support12002 may be rigid and have high optical transmission. Further, axialsupport 12002 may be disposed externally to compartment 1000 and includea curved convex vertex 45050 disposed in communication with vertex 2010of optical surface 2002. Compartment 1000 may include rigid opticalsurface 45014 and compliant edge support 2004. Support 27010 may bedisposed between of axial support 12002 and optical surface 2002. Firstfluid 100 may be disposed in compartment 1000. An index-matching secondfluid 45030 may be disposed in external compartment 45040 locatedbetween axial support 12002 and optical surface 2002. Actuator 27014 maybe mounted between housing 27018 and axial support 12002. In operation,actuator 27014 may deliver an axial motive force to axial support 12002.Such motive force may result in a pin-on-ring load being applied tooptical surface 2002 through axial support and perforated support 30002.Additionally as a result of the motive force, a ring-on-ring load may beapplied to optical surface 2002 through supports 27010, 30002.

FIG. 37 is a three-dimensional cross-sectional view of fluidic lenselement 46000 similar to the structure depicted in FIG. 36. However, inFIG. 37, an additional actuator 46002 is disposed in communication withaxial support 12002 and support 27010. In operation, actuator 27014 maydeliver an axial motive force to axial support 12002. Such motive forcemay result in a pin-on-ring load being applied to optical surface 2002through axial support 12002 and perforated support 30002. Additionally,actuator 46002 may deliver an axial motive force to optical surface 2002and axial support 2004. Such motive force may result in a ring-on-ringload being applied to optical surface 2002 through supports 27010,30002. Such independent control of multiple applied loads on opticalsurface 2002 may enable independent control over spherical curvature andasphericity of deflection of optical surface 2002.

FIG. 38 is a three-dimensional cross-sectional view of fluidic lenselement 47000 similar to the structure depicted in FIG. 37. However, inFIG. 38 actuator 46002 may be mounted between adjustable housing member28004 and a ring-shaped support 47004. Support 47004 may be fastened torigid optical surface 45014. Support 27010 may be mounted to housingprotrusion 47006. Actuator 27014 may be mounted to a second housingadjustable housing member 47020. In operation, actuator 46002 maydeliver an axial motive force to support 47004, resulting in aring-on-ring load being applied to optical surface 2002 through supports27010, 30002. Additionally, actuator 27014 may deliver an axial motiveforce to axial support 12002. Such motive force may result in apin-on-ring load being applied to optical surface 2002 through axialsupport 12002 and perforated support 30002.

FIG. 39 is a three-dimensional cross-sectional view of an adaptivefluidic optical device 48000 similar to the device depictedschematically in FIG. 9. Compartment 1000 is bounded by optical surface2002 and axial support 12002. In the present embodiment, axial support12002 may be disposed with curved convex vertex 45050 internal tocompartment 1000 and in communication with vertex 2010 of opticalsurface 2002. Compartment is additionally bounded by compliant reservoirbladder 43002. Portions of reservoir may be disposed in communicationwith axial support 12002 and optical surface 2002. In this fashion,reservoir bladder 43002 may form a seal with optical surface 2002, andaxial support 12002, thereby sealing compartment 1000. Compartment 1000may be at least partially filled with fluid 100. Actuator 27014 may bemounted between housing 27018 and support 27010. Adjustable housingmember 28004 is disposed in communication with axial support 12002. Inthis fashion, the axial position of adjustable housing member 28004 maybe adjusted in order to provide a desired amount of “pre-load” (orcompression) to compartment 1000, actuator 27014, and/or device 48000.In operation, actuator 27014 may deliver an axial motive force tosupport 27010. Such motive force may result in a pin-on-ring load beingapplied to optical surface 2002 through axial support 12002 and support27010. Such pin-on-ring applied load may result in the bendingdeflection of optical surface 2002. In response to any volume excursionsresulting from deflection of optical surface 2002, bellows member 33050may deform in order to accommodate such fluid excursions and reduce oreliminate any residual fluid pressure.

FIG. 40 is a three-dimensional cross-sectional view of an adaptivefluidic optical device 49000 similar to the device depicted in FIG. 26.The present embodiment demonstrates an alternative method to produce auniformly distributed applied load. A compartment 1000 is bounded byoptical surfaces 2002, 2012 and a bellows support 33002. Actuator ismounted to a housing (not shown). Rigid optical surface 45014 may bedisposed in communication with support 27012. Support 27012 forms a sealwith optical surfaces 45014, 2012. In this fashion, an externalcompartment 49004 is bounded by optical surfaces 45014, 2012 and support27012. External compartment 49004 may be filled with a second fluid (orgas or other medium) 45030 having desired thermal properties (includingcoefficient of thermal expansion). Temperature control element 49008(for example, a thermoelectric or piezoelectric heat transfer device, orNiCr (or “nichrome”) coating or wire.) may be disposed proximal to rigidoptical surface 45014 and in thermal communication with compartment49004 and/or fluid 45030. In this fashion, a change in temperature oftemperature control element 49008 may cause a change in temperature offluid 45030. Likewise, the pressure in compartment 49004 will change inaccordance with the thermal expansion properties of fluid 45030. Inoperation, actuator 27014 may deliver a ring-on-ring load to opticalsurface 2002 through supports 27010, 33002. Additionally, a uniformlydistributed load (for example, gas- or fluid pressure) may be applied tooptical surface 2012 through a change in pressure in compartment 49004due to the heating and/or cooling of fluid 45030.

FIG. 41 is a detailed view of the edge region of lens element 49000depicted in FIG. 29. Compartments 1000, 49004 are sealed by supports33002, 27010, respectively.

FIG. 42 is a detailed view of rigid optical surface 45014. Heatingelement 49008 may be configured in a circular pattern concentric withthe edge of rigid optical surface 45014 and include exposed electricalcontacts 39220, 39222.

FIG. 43 is a cross-sectional side view of an adaptive fluidic opticaldevice 42000 similar to the one depicted schematically in FIG. 6.Compartment 1000 is partially bounded by optical surfaces 2002, 2012 andsupports 27010, 27012. Compartment may additionally be bounded bysupport frames 41100, 41102 and diaphragm seal 41110. Support frames41100, 41102 may be structural frames providing a rigid surface to mountsupports 27010, 27012, respectively. For example, support frames 41100,41102 may be fabricated from machined aluminum, steel or rigidmachinable plastic, and may be of similar shape to that of supports27010, 27012 (for example, ring-shaped). Supports 27010, 27012 may bebonded to support frames 41100, 41102, forming a seal. Diaphragm seal41110 may include a flexible film, seal or support and may be fastenedto support frames 41100, 41102, forming a seal. Diaphragm seal 41110 maybe configured in any desirable shape; for example, in the case wheresupport frames 41100, 41102 are ring-shaped and concentrically disposedto each other, diaphragm seal 41110 may be formed in the shape of a ringor film annulus. Further, diaphragm seal 41110 may be a film andfastened to support frames 41100, 41102 with pre-tension. A supportframe 41102 may include one or more fluid channel 35010 and fluidreservoir 41120. Fluid reservoir 41120 may be similar to a channel orcavity disposed in a support frame 41102 for holding and transportingfluid 100. Fluid channel 35010 provides fluid communication betweencompartment 1000 and fluid reservoir 41120. Fluid reservoir 41120 may besealed with a bladder diaphragm 41130. Bladder diaphragm 41130 may be acompliant film or seal and is capable of deflecting in response toresidual fluid pressure. In FIG. 43, the device 42000 is shown in anun-actuated (or “first actuation”) state wherein optical surfaces 2002,2012, diaphragm seal 41110 and bladder diaphragm 41130 are substantiallyundeflected, and, hence, residual fluid pressure in compartment 1000 issubstantially zero.

FIG. 44 is a cross-sectional side view of an adaptive fluidic opticaldevice 42000 similar to the device depicted in FIG. 43. However, in FIG.44, device 42000 is shown in a second actuation state wherein opticalsurfaces 2002, 2012, diaphragm seal 41110 and bladder diaphragm 41130are deflected. An actuator (not shown) provides an axial motive force,resulting in displacing support frames 41100, 41102 axially toward eachother. As a result of displacement of support frames 41100, 41102,diaphragm seal 41110 is brought into a state of increased tension.Further, as a result of displacement of support frames 41100, 41102,optical surfaces 2002, 2012 are subjected to a ring-on-ring applied loadthrough supports 30002, 27010, 27012, and undergo bending deflection. InFIG. 44, support 30002 is configured with a first support radius, R1(indicated by arrow 41200). As a result of such first support radius andactuation of device, a positive residual pressure (indicated by arrow42100) is present in compartment 1000. Such positive residual pressureresults in the outward deflection of bladder diaphragm 41130. In thisfashion, bladder diaphragm 41130 increases the effective volume of fluidreservoir 41120 such that residual fluid pressure is reduced oreliminated. Support frames 41100, 41102 may be configured such that in astate of maximum axial displacement, they may bottom out (or stop)against each other. In such case one or more rim fluid channel 42200 maybe disposed in one or more of Support frames 41100, 41102. Such rimfluid channel 42200 may be similar to fluid channels 35010 (see FIG. 43)and provide fluid communication between compartment 1000 and fluidreservoir 41120 when support frames 41100, 41102 are bottomed outagainst each other. As an optional alternative embodiment, if diaphragmseal 41110 is configured with sufficient compliance, it may perform theadditional function of acting similar to a bellows and relievingresidual fluidic pressure. In this fashion, diaphragm seal 41110 mayobviate the need for, and, hence, enable the elimination of, bladderdiaphragm 41130.

FIG. 45 is a cross-sectional side view of an adaptive fluidic opticaldevice 42000 similar to the device depicted in FIG. 44 in secondactuation state. However, in FIG. 45, support 30002 is configured with asecond support radius, R2 (indicated by arrow 41300). As a result ofsuch second support radius and actuation of device, zero residualpressure is present in compartment 1000. Such lack of residual pressureresults in no deflection of bladder diaphragm 41130.

FIG. 46 is a cross-sectional side view of an adaptive fluidic opticaldevice 42000 similar to the device depicted in FIG. 44 in thirdactuation state. However, in FIG. 46, support 30002 is configured with athird support radius, R3 (indicated by arrow 41400). As a result of suchthird support radius and actuation of device, negative residual pressureis present in compartment 1000. Such lack of residual pressure resultsin no deflection of bladder diaphragm 41130.

FIG. 47 is a cross-sectional view of an alternative embodiment of anadaptive fluidic optical device 50000, similar to the device depictedschematically in FIG. 6. Compartment 1000 is at least partially boundedby optical surfaces 2002, 2012, supports 27010, 27012, and support frame41100. Fluid 100 may be disposed in compartment 1000. Rim fluid channel42200 and bladder diaphragm 41130 may be disposed in a radial fashion insupport frame 41100. First support armature 45400 and second supportarmature 45402 may be disposed external to compartment 1000. Supportarmatures 45400, 45402 may include support members 45500, 45502 and maybe substantially rigid. Support members 45500, 45502 may be disposed incommunication with optical surfaces 2002, 2012. Further, support members45500, 45502 may include portions with rounded cross-sectional shape inorder to provide a concentrated applied load to optical surfaces 2002,2012. Support armatures 45400, 45402 may be disposed as part of or incommunication with a housing (not shown), and/or actuator (not shown).In operation, actuator (not shown) may provide a motive force, therebyresulting in an axial displacement of support armatures 45400, 45402with respect to each other. Such displacement of support armatures45400, 45402 may result in a concentrated bending load being applied tooptical surfaces 2002, 2012. For example, in the case of ring-shapedsupport members 45500, 45502 and supports 27010, 27012, said bendingload may be similar to a ring-on-ring load. In FIG. 47, device 50000 isshown in a first actuation state wherein no substantial load is appliedand optical surfaces 2002, 2012 are substantially undeflected. Further,in first actuation state, zero residual fluid pressure may be present inchamber 1000, leaving bladder diaphragm 41130 substantially undeflected.

FIG. 48 is a cross-sectional view of adaptive fluidic optical device50000, similar to the device depicted FIG. 47. However, in FIG. 48,device 50000 is shown in a second actuation state. In second actuationstate, support armatures 45400, 45402 are axially displaced with respectto each other (indicated by arrow 45600). As a result of displacement ofsupport armatures 45400, 45402, applied ring-on-ring loads are deliveredto optical surface 2002 through support 27010 and support member 45500,and to optical surface 2012 through support 27012 and support member45502. In response to applied loads, optical surfaces 2002, 2012 deflectin a concave fashion (i.e., inward toward the center of compartment1000). Further, as a result of deflection of optical surfaces 2002,2012, positive residual fluid pressure may be present in compartment1000, resulting in a convex (or outward) deflection of bladder diaphragm41130.

FIG. 49 is an alternative configuration of the device 50000 depicted inFIG. 48. However, in FIG. 49, at least a portion of rim fluid channel42200 and/or bladder diaphragm 41130 may be disposed in an axial fashionin support frame 41100.

FIG. 50 is an alternative configuration of the device 50000 depicted inFIG. 48. However, in FIG. 50, rim fluid channel 42200 may employopenings 35020, capillary forces and/or electrowetting to control fluid100 (similar to fluid channels 35010; see FIG. 29) and/or fluid pressurein compartment 1000.

FIG. 51 is an alternative configuration of the device 50000 depicted inFIG. 48. However, in FIG. 51, supports 27010, 27012 may be configuredintegral with support frame 41100. Further supports 27010, 27012 mayinclude rounded cross-sections, and may be substantially rigid andfastened to optical surfaces 2002, 2012 with a compliant adhesive(indicated by meniscuses 43016, 43018), thereby sealing compartment1000. In this fashion supports 27010, 27012 may function similarly tosimple supports in delivering concentrated applied loads to opticalsurfaces 2002, 2012 and providing a seal to compartment 1000. Actuationof device 50000 may result in residual fluid pressure which may resultin the deflection of bladder diaphragm 41130.

FIG. 52 shows a cross-section of an adaptive fluidic optical device51000 according to a preferred embodiment of the present invention.Compartment 1000 may include and be partially bounded by first opticalsurface 2002 and second optical surface 2012. First optical surface 2002may be similar to a Kirchhoff plate or exhibit deflection dominated bybending (i.e., it may exhibit a ‘bending modulus’). Second opticalsurface 2012 may be rigid or similar to a thick plate. Compartment 1000may be further bounded by diaphragm seal 41110, perforated support30002, support frame 41100, and support 27010. Actuator 51100 may besimilar to an electromagnet and include solenoid bobbin 51110, solenoidcasing 51120, solenoid winding 51130 and solenoid armature 51140. One ormore of solenoid bobbin 51110, solenoid casing 51120, solenoid winding51130 and solenoid armature 51140, and/or any other part of actuator51100 may include ferromagnetic materials (such as low-carbon steel,magnetic iron and/or electromagnetic iron), permanent magneticmaterials, any other desirable material for use in electromagnets,and/or materials having any desired properties including remanentmagnetism, coercivity, permeability, and/or core loss. Compartment 1000may be filled with fluid 100. One or more of optical surface 2012,diaphragm seal 41110 and perforated support 30002 may be disposed incommunication with solenoid bobbin 51110. Solenoid armature 51140 may bedisposed in communication with support frame 41100. Solenoid casing51120 may be fastened to housing 27018 with threading 51150, and/orretainer rings 51200, 51210, 51220.

FIG. 53 shows a close-up cross-section view of device 51000 similar tothe structure depicted in FIG. 52. Solenoid winding 51130 may be anelectrically conductive wire wound into a solenoidal coil. Solenoidbobbin 51110, solenoid casing 51120 and solenoid armature 51140 may forma substantially toroidally shaped shell encasing solenoid winding 51130.Solenoid bobbin 51110, solenoid casing 51120 and solenoid winding 51130may be substantially fixed in position with respect to each other.Solenoid armature 51140 (similar to a solenoid plunger) is the movingcomponent of actuator 51100 and may be configured for translation in adirection parallel to the axis of solenoid winding 51130 (which mayparallel to the optical axis and is indicated by arrow 51310). Inun-actuated state, solenoid armature 51140 may be disposed with an airgap 51400 positioned between it and solenoid casing 51120. In operation,actuator 51100 may be controlled by passing an electric current throughsolenoid winding 51130, thereby inducing a toroidally-shaped magneticcircuit (indicated by arrows 51300) confined substantially in solenoidbobbin 51110, solenoid casing 51120 and solenoid armature 51140. Inresponse to magnetic flux in magnetic circuit 51300, solenoid armature51140 may move in a direction that increases the magnetic flux densityin (or, decreases the reluctance of) magnetic circuit 51300. Forexample, solenoid armature 51140 may be substantially composed of iron.In FIG. 53, support 27010 and optical surface 2002 are hidden in orderto provide visibility of support 30002 and optional fluid pass-throughs30004 and diaphragm seal 41110.

FIG. 54 shows a detailed close-up cross-section view of device 51000similar to the structure depicted in FIG. 52. Support 27010 may bedisposed in communication with optical surface and support frame 41100in the proximity of the edge of optical surface 2002. In this fashion,support may function similarly to a fixed, compliant, or simple edgesupport to optical surface 2002. Likewise, perforated support 30002 maybe disposed in communication with, and function similarly to, a simplesupport to optical surface 2002 and may optical surface 2002. Solenoidarmature 51140 may be fastened to support frame 41100. In response toelectromagnetic force from magnetic circuit 51300, solenoid armature51140 and support frame 41100 may move axially (indicated by arrow51310) toward solenoid casing 51120, thereby reducing the size of airgap 51400. Such axial motion of support frame 41100 may deliver anaxially directed motive force to the edge of optical surface 2002. Inresponse to such motive force at the edge of optical surface 2002,support 30002 may provide a reactive force and simple support to opticalsurface 2002. In this fashion, a ring-on-ring type load may be providedto, and cause the bending deflection of, optical surface 2002. Retainerring 51200 may serve as a physical stop for limiting the axial travel ofsupport frame 41100.

FIG. 55 is a three-dimensional cross-section view of an adaptive fluidicoptical device 54000, similar to the device depicted in FIG. 19.Compartment 1000 may be at least partially bounded by optical surfaces2002, 2012, supports 27010, 27012, 2004, support frame 41100, andhousing 27018. Housing 27018 may additionally function in a fashionsimilar to support frame 41100 wherein it may serve as a mount for asupport and/or optical surface. Support 30002 further may includespider-leg (not shown) and outer-rim (not shown) protrusions to assistin positioning of support 30002 within compartment 1000. Support 30002may be perforated in order to allow fluid communication across eitherside of it, or may not be perforated in order to prevent fluidcommunication as desired. Actuator 54300 may be disposed to provide anaxially directed motive force to support frame 41100. Actuator 54300 mayfurther include a plurality of actuator members 27014, 54100, 54110,54120, 53130, which may be stacked actuators (for example, a stack ofpiezoelectric ring benders or electroactive polymer actuators) or asingular actuator configured for increased stroke and/or force (forexample, a singular electroactive polymer actuator folded multiple timesthereby forming stacked actuator layers). In the case of actuator 54300comprising stacked discrete members, a plurality of actuator supports54200, 54210, 54220, 54230, 54240 may be disposed in communication withone or more actuator members in the stack. Actuator supports 54200,54210, 54220, 54230, 54240 may be at least partially electricallyconductive and/or insulating, in order to provide desired electricalcommunication to actuator members 27014, 54100, 54110, 54120, 53130.Further, actuator supports 54200, 54210, 54220, 54230, 54240 may be atleast partially stiff and/or compliant in order to provide desiredmechanical support to actuator members 27014, 54100, 54110, 54120,53130. Additionally, one or more conductive straps 54400 may be disposedin order to provide desired electrical communication between actuatormembers in the stack. For example, conductive strap 54400 may connectthe piezoceramic electrodes of actuator elements 54130, 54120 to eachother. Similarly, conductive support 54230 may connect the metallicshims of actuator elements 54130, 54120 to each other. In this fashion,a plurality of such conductive straps and supports may be employed toelectrically and mechanically connect all actuator members in a desiredconfiguration. Support 54240 may be disposed in communication withadjustable housing member 28004, wherein the axial position ofadjustable housing member 28004 may be adjusted in order to provide adesired preload to actuator 54300. The position of adjustable housingmember 28004 may be set by any desirable method, for example, threads54500 between adjustable housing member 28004 and housing 27018. Inoperation, actuator 54300 may deliver an axial load to optical surface2002 through support 27010. Likewise, optical surface 2002 maycommunicate such axial load to optical surface 2012 through support30002. In this fashion, a first ring-on-ring load may be delivered tooptical surface 2002 between supports 27010, 30002, and a secondring-on-ring load may be delivered to optical surface 2012 betweensupports 27012, 30002. Such ring-on-ring loads may result in thedeflection of optical surfaces 2002, 2012. Residual fluid pressure maybe controlled by fluid channels 35010 and bladder diaphragm 41130.Additionally, fluid 100 may be introduced into compartment 1000 viafluid channel 35010 (prior to sealing fluid channel 35010 with bladderdiaphragm 41130), wherein fluid channel 35010 may function similarly toa fill hole as understood in the field of microfluidic deviceengineering.

FIG. 56 is a three-dimensional cross-section view of an adaptive fluidicoptical device 56000, similar to the device depicted in FIG. 6. Device56,000 is configured to operate similarly to a cylindrical lens havingadjustable focal length. Compartment 1000 may be at least partiallybounded by optical surfaces 2002, 2012, housing 27018, and sidewallmembers 56200, 56202. In one embodiment, optical surface 2002 may bebendable and similar to a Kirchhoff plate, while optical surface 2012may be substantially rigid. Supports 30002, 56100 may be substantiallylinear and disposed parallel to each other, thereby enabling the bendingof optical surface 2002 along a single axis. Actuators 54300, 56300 maybe disposed in the proximity of the edges optical surface 2002 andprovide an axially-directed motive force to the edges of optical surface2002. In this fashion, actuators 54300, 56300 and supports 30002, 56100may deliver a bending load to optical surface 2002 similar to a 4-pointload wherein optical surface 2002 may bend about an axis substantiallyparallel to supports 30002, 56100. Supports 30002, 56100 may beperforated with fluid pass-throughs (not shown). Sidewall members 56200,56202 may be at least partially compliant and accommodate for bending ofoptical surface 2002 while still maintaining a seal on the sidewalls ofcompartment 1000. Preferably, sidewall members are more compliant thanoptical surface 2002 and may easily deflect or deform in response todeflection of optical surface 2002. In FIG. 56, sidewall member 56200 isshown partially removed in to provide visibility to the internal regionof compartment 1000, however it may completely seal the side ofcompartment, spanning from actuator 54300 to actuator 56300.

FIG. 57 is a detailed three-dimensional cross-section view of anadaptive fluidic optical device 56000, similar to the device depicted inFIG. 56. Actuator 54300 may include a plurality or stack of individualactuator members. Fluid channel 35010 and bladder diaphragm 41130 may beprovided in optical surface 2012 or any other desirable part of thedevice 56000 in order to control residual fluid pressure.

FIG. 58 is a partial cross-section view of an adaptive fluidic opticaldevice 56000, similar to the device depicted in FIG. 56. Optical surface2002 is shown in a deflected state as a result of the applied load(which, as described above may similar to 4-point loading). Supports27010, 27012 may be disposed in communication with actuator 54300 andoptical surface 2002 in order to deliver motive force from actuator54300 to optical surface 2002. In response to deflection of opticalsurface 2002, and sidewall members 56200, 56202 may undergo elasticdeformation (for example, tension).

It is understood that the fluid or any fluidic element of the device maycomprise fluid, liquid, gas, gel, plasma or solid chosen for itsperformance characteristics including optical, mechanical, physical andchemical properties.

It is also understood that the fluid or any type of optical surface ofany embodiment of the device may be substituted and/or combined with anyother type of optical surface. For example, a Kirchhoff plate-typeoptical surface in an embodiment may be replaced with a rigid opticalsurface.

It is further understood that a compartment may be closed (i.e., sealed)or open (i.e., not sealed). For example, a closed compartment maycomprise two optical surfaces and a ring-shaped support forming a sealaround a fluid or liquid. Alternatively, one example of an opencompartment may comprise two optical surfaces and a reservoir havingopen capillary channels generally bounding a fluid or liquid. As afurther example of an open compartment, two optical surfaces may bedisposed in communication on either side of a volume of gel, elastomer,polymer, solid or other desirable material. The gel may have sufficientviscosity and/or other desirable properties (for example, low durometer)such that it will not run, thereby eliminating the need for confinement(or a seal) around its perimeter by a reservoir, support, sidewall orother fluid containment structure.

It is also understood that multiple elements of the present device maybe combined and formed as “integrated” (or “unitary” or “monolithic”)units or parts.

The reader's attention is directed to all papers and documents which arefiled concurrently with this specification and which are open to publicinspection with this specification, and the contents of all such papersand documents incorporated herein by reference.

All the features disclosed in this specification (including anyaccompanying claims, abstract and drawings) may be replaced byalternative features serving the same, equivalent or similar purpose,unless expressly stated otherwise. Thus, unless expressly statedotherwise, each feature disclosed is one example only of a genericseries of equivalent or similar features.

While the above is a complete description of the preferred embodiment ofthe present invention, it is possible to use various alternatives,modifications and equivalents. Therefore, the scope of the presentinvention should be determined not with reference to the abovedescription but should, instead, be determined with reference to theappended claims, along with their full scope of equivalents. In theclaims that follow, the indefinite article “A”, or “An” refers to aquantity of one or more of the item following the article, except whereexpressly stated otherwise. The appended claims are not to beinterpreted as including means-plus-function limitations, unless such alimitation is explicitly recited in a given claim using the phrase“means for.” Any feature described herein, whether preferred or not, maybe combined with any other feature, whether preferred or not.

We claim:
 1. A fluidic optical device, comprising: a fluidic lens havinga compartment comprising; an optical surface; wherein the opticalsurface is stiff and configured for bending deflection in response to anapplied load; a first support member; a second support member; whereinthe first and second support members are configured to apply aconcentrated concentric load to one or more of the optical surfaces;wherein the compartment is filled with a fluid; wherein the applicationof a load to one or more of the support members results in theapplication of the concentrated concentric load to the optical surfacethereby resulting in a bending deflection of the optical surface andthereby changing one or more optical properties of the fluidic opticaldevice and resulting in a residual fluid pressure in the compartment. 2.The device in accordance with claim 1 wherein the deflection is affectedby a bending stress.
 3. The device in accordance with claim 1 whereinthe deflection is affected by a diaphragm stress.
 4. The device inaccordance with claim 1 wherein the deflection is dominated by a bendingstress.
 5. The device in accordance with claim 1 wherein the deflectionis dominated by a diaphragm stress.
 6. The device in accordance withclaim 1 wherein the deflection results in a negative residual fluidpressure in the compartment.
 7. The device in accordance with claim 1wherein the deflection results in a positive residual fluid pressure inthe compartment.
 8. The device in accordance with claim 1 wherein thedeflection results in zero residual fluid pressure in the compartment.9. The device in accordance with claim 1 further comprising a bladdermember configured to reduce residual fluid pressure in the compartment.10. The device in accordance with claim 1 further comprising a bladdermember configured to reduce residual fluid pressure in the compartmentresulting from the deflection.
 11. A fluidic optical device, comprising:a fluidic lens having a compartment comprising; an optical surface;wherein the optical surface is stiff and configured for bendingdeflection in response to an applied load; a first support member; asecond support member; wherein the first and second support members areconfigured to apply a concentrated concentric load to the opticalsurface; wherein the compartment is filled with a fluid; wherein theapplication of a load to one or more of the support members results inthe application of the concentrated concentric load to the opticalsurface thereby resulting in a bending deflection of the optical surfaceand thereby changing one or more optical properties of the fluidicoptical device, wherein the deflection results in zero residual fluidpressure in the compartment.
 12. The device in accordance with claim 11wherein the deflection is affected by a bending stress.
 13. The devicein accordance with claim 11 wherein the deflection is affected by adiaphragm stress.
 14. The device in accordance with claim 11 wherein thedeflection is dominated by a bending stress.
 15. The device inaccordance with claim 11 wherein the deflection is dominated by adiaphragm stress.
 16. The device in accordance with claim 11 wherein thedeflection results in a negative residual fluid pressure in thecompartment.
 17. The device in accordance with claim 11 wherein thedeflection results in a positive residual fluid pressure in thecompartment.
 18. The device in accordance with claim 11 wherein thedeflection results in zero residual fluid pressure in the compartment.19. The device in accordance with claim 11 further comprising a bladdermember configured to reduce residual fluid pressure in the compartment.20. The device in accordance with claim 11 further comprising a bladdermember configured to reduce residual fluid pressure in the compartmentresulting from the deflection.